• HVYRAIN: Excessive Rainfa

    From Mike Powell@618:250/10 to All on Sat May 16 08:45:27 2026
    FOUS30 KWBC 160737
    QPFERD

    Excessive Rainfall Discussion
    NWS Weather Prediction Center College Park MD
    337 AM EDT Sat May 16 2026

    Day 1
    Valid 12Z Sat May 16 2026 - 12Z Sun May 17 2026

    ...THERE IS A MARGINAL RISK OF EXCESSIVE RAINFALL FOR PORTIONS OF
    THE LOWER TO MID OHIO VALLEY AS WELL AS PORTIONS OF THE CENTRAL PLAINS...

    ...Lower to Mid Ohio Valley...

    Areas of convection that will form along a warm front at the nose
    of a low-level jet are expected to develop during peak heating
    today across the lower to mid Ohio Valley. While the main branch of
    the low level jet remains oriented south to north over the Plains,
    the side branch over the Ohio Valley will be oriented southwest to
    northeast. This will promote training storms with backbuilding
    convection, while the primary storm movement is towards the
    east. Training storms are most likely to develop in the Marginal
    Risk area. Despite very dry soils over the region, which will limit
    the flash flooding risk, some urban areas are threatened with the
    possibility of training storms, so the Marginal remains in place.

    ...Central Plains...

    During the early evening hours, showers and thunderstorms will
    develop along the nose of a robust low level jet transporting
    abundant moisture and instability north from the Gulf into the
    central Plains. A warm front at the leading edge of the warm, moist
    air mass will interact with a strengthening upper level shortwave
    and a developing surface low over southwest Kansas to support the
    convective activity. While some of the convection will develop into
    a highly progressive bowing segment, it's likely that the southern
    end of the bow will get "stuck" and remain largely in place as
    additional convection backbuilds westward, generally along the
    Iowa/Missouri border. Repeating rounds of convection are possible,
    and likely to be of somewhat greater vigor than the ongoing
    convection across Iowa. Any overlap of the convection this evening
    with the rainfall footprint of the ongoing storms present over
    central Iowa could also locally increase the flash flooding risk.
    However, at the moment any overlap should be minimal, as the
    strongest storms with the greatest flash flooding risk are expected
    along the Missouri/Iowa border, which did not see any meaningful
    rain last night. Thus, the Marginal remains in place as soils in
    the region remain very dry.

    ...Elsewhere...

    In between the areas of storms over eastern Missouri/western
    Illinois, a "break" is likely to remain, separating the footprints
    of the two areas of storms. With minimal rainfall expected along
    the Mississippi River near St. Louis, the inherited Marginal was
    removed, leaving two separate Marginal Risk areas.

    Wegman


    Day 2
    Valid 12Z Sun May 17 2026 - 12Z Mon May 18 2026

    ...THERE IS A MARGINAL RISK OF EXCESSIVE RAINFALL FOR PORTIONS OF
    THE UPPER MIDWEST...

    A robust low level jet feeding plentiful moisture ahead of a
    developing low over the Plains will provide the moisture and
    instability needed for numerous thunderstorms across a large
    portion of the upper Midwest from far eastern Nebraska northeast
    through the Arrowhead of Minnesota. The storms are likely to be
    their strongest Sunday night. This will coincide with the diurnal
    strengthening of the low level jet. Clusters of showers and storms
    will develop with increasing forcing ahead of a slow moving upper
    level trough over the High Plains. The storms are likely to train
    as several rounds of upper level energy support several rounds of
    storm clusters. Much of Iowa saw beneficial rains overnight
    tonight, such that by Sunday night, the soils will still have some
    moisture left over. Urban concerns, especially in and around the
    Twin Cities could also locally increase the flash flooding threat.
    Significant dry time in between the storms should limit the
    flooding threat such that the inherited Marginal still looks good,
    and few changes were needed.

    Wegman


    Day 3
    Valid 12Z Mon May 18 2026 - 12Z Tue May 19 2026

    ...THERE IS A SLIGHT RISK OF EXCESSIVE RAINFALL FROM PORTIONS OF
    THE CENTRAL PLAINS THROUGH THE UPPER MIDWEST...

    An upper level trough that has been "stuck" over the northern High
    Plains for a few days will finally begin to eject across the
    northern Plains on Monday. This will occur because a strong
    shortwave on its southern edge near the 4 Corners region will help
    to nudge the trough eastward. This strong shortwave will run into
    plentiful Gulf moisture that will continue streaming northward
    across the middle of the country, as it has been doing for the past
    several days. A cold front on the northwestern boundary of that low
    level jet will provide ample surface forcing for the storms. The
    initial meeting of the warm, moist air mass to the east and the
    cooler, drier air mass over the northern Plains will be along the
    Missouri River from far northeastern Kansas north across much of
    western Iowa. This will be the corridor where the heaviest rainfall
    totals are expected on Monday through Monday night. This is the
    same region that will have been hit by multiple days of scattered
    heavy rainfall. By Day 3/Monday, soils should be much closer to
    saturation. Thus, with the greatest rainfall amounts areally
    expected on Monday, the flooding threat increases into the Slight
    Risk category. Any storms that form will continue to rapidly
    progress northeastward into the upper Mississippi Valley. This area
    too will have seen multiple days of storms by Monday. Thus,
    expecting wetter than normal soil conditions in most areas by
    Monday, the Slight Risk area was expanded northward to cover the
    upper Mississippi Valley to the western tip of Lake Superior.

    There remains some uncertainty as to where the axis of heaviest
    rainfall will set up. Thus, the surrounding Marginal covers
    extensive real estate east of the Slight from northern Illinois
    north through much of the U.P. of Michigan. While expected rainfall
    totals are lower in this region, greater urban concerns are present
    in this area, which supports the Marginal Risk.

    Wegman
    $$
    --- SBBSecho 3.28-Linux
    * Origin: Capitol City Online (618:250/10)
  • From Mike Powell@618:250/10 to All on Sun May 17 08:11:42 2026
    FOUS30 KWBC 170703
    QPFERD

    Excessive Rainfall Discussion
    NWS Weather Prediction Center College Park MD
    303 AM EDT Sun May 17 2026

    Day 1
    Valid 12Z Sun May 17 2026 - 12Z Mon May 18 2026

    ...THERE IS A MARGINAL RISK OF EXCESSIVE RAINFALL FOR PORTIONS OF
    THE CENTRAL PLAINS TO THE UPPER MIDWEST...

    A pair of shortwave troughs tracking northeast on the downwind side
    of a slow moving longwave trough over the Intermountain West will
    provide upper level forcing for several rounds of thunderstorms to
    impact a large area from Kansas through the upper Great Lakes. A
    fully open Gulf and associated moisture plume will continue to
    advect northward up the Plains and Mississippi River. This will
    keep PWATs consistently above 1.25 inches, with many areas above
    1.5 inches. This influx of moisture will support and instability
    will support both storms capable of heavy rainfall, as well as
    development and redevelopment of storms in this favorable weather
    regime. For the most part, due to fast upper level flow, the storms
    will likely organize into fast moving lines/segments, which should
    work to keep rainfall totals manageable in any one area. The
    greatest area of concern stretches from southeastern Nebraska east
    along the Iowa/Missouri border, where multiple inches of rain have
    fallen overnight last night. Thus, any backbuilding or holdups in
    any lines of storms could have outsized flooding impacts. A short-
    fused Slight may be needed once again in this general area if
    rainfall totals today come up further.

    For southeastern Louisiana, the inherited MRGL was removed. Nearly
    all of the guidance shows only light showers expected to impact
    that area, with only a one or two showing one isolated storm.
    Further, high FFGs should preclude any flooding even if that one
    storm does form.

    Wegman


    Day 2
    Valid 12Z Mon May 18 2026 - 12Z Tue May 19 2026

    ...THERE IS A SLIGHT RISK OF EXCESSIVE RAINFALL FROM THE CENTRAL
    PLAINS TO THE UPPER MISSISSIPPI VALLEY...

    Relatively few changes were needed to the outlook for this likely
    busiest day of the upcoming three. A strong shortwave making up the
    base of the longwave trough over the Rockies will finally eject out
    over the Plains on Monday. As that shortwave interacts with
    plentiful Gulf moisture streaming north up the Plains, renewed
    lines of showers and storms are expected to develop across the
    Slight Risk area. Since the storm motion will be towards the
    northeast, largely parallel to the moisture and instability plume
    emanating from the Gulf, backbuilding will be a greater
    possibility than in previous days. Several of the high resolution
    model guidance show that there could be multiple rounds of storms
    to impact the area from northeast Kansas through southwestern Iowa,
    especially in the late afternoon through the first half of the
    overnight. This area is currently getting very hard-hit with heavy
    rain from a very slow-moving MCS that has been producing multiple
    inch per hour rainfall rates and numerous instances of flash
    flooding. Thus, the soils have become very saturated in some areas.
    Following potential heavy rain during the day 1/Sunday period,
    much more rain is expected in this region again on Monday. A
    higher-end Slight covers the aforementioned region from northeast
    Kansas through the southwest corner of Iowa. Should multiple inch
    per hour rates materialize again in this same region, a Moderate
    Risk upgrade will need to be considered with future updates.

    Wegman


    Day 3
    Valid 12Z Tue May 19 2026 - 12Z Wed May 20 2026

    ...THERE IS A MARGINAL RISK OF EXCESSIVE RAINFALL FROM THE SOUTHERN
    PLAINS THROUGH THE LOWER OHIO VALLEY...

    The inherited Slight Risk for the southeastern half of Oklahoma was
    removed with this update. Guidance has been understandably
    struggling with the placement of expected rainfall/convection
    across this region. Since there's excellent agreement that the axis
    of heaviest rainfall will shift well south of the area expected to
    be hit with heavy rain in days 1 and 2, the region of greatest
    impact is an area where soils have dried out and will likely be
    very receptive to beneficial rainfall. Since guidance is in poor
    agreement on where the storms will be most persistent, instead
    broad brushing much of the Marginal Risk area with anywhere from a
    half inch to 1.25 inches, have opted to leave the large Marginal in
    place. None of the guidance particularly favors southeastern
    Oklahoma for any heavier amounts that anywhere else, especially
    further south into Texas. Expect that should a new Slight be needed
    with a future update, it will be over a portion and not into
    Oklahoma, which sits at the back/northwestern edge of the heavier rain axis.

    Wegman
    $$
    --- SBBSecho 3.28-Linux
    * Origin: Capitol City Online (618:250/10)
  • From Mike Powell@618:250/10 to All on Sun May 31 08:48:12 2026
    FOUS30 KWBC 310825
    QPFERD

    Excessive Rainfall Discussion
    NWS Weather Prediction Center College Park MD
    425 AM EDT Sun May 31 2026

    Day 1
    Valid 12Z Sun May 31 2026 - 12Z Mon Jun 01 2026

    ...THERE IS A SLIGHT RISK OF EXCESSIVE RAINFALL OVER PORTIONS OF
    THE NORTHERN ROCKIES AND THE SOUTHEAST UNITED STATES...

    Northern Rockies...
    With rainfall on-going from Saturday due to a slow moving mid- and
    upper-level system over the northern Rockies...opted to keep
    portions of Montana and nearby Wyoming and the far western Dakotas
    in a Slight Risk area during the new Day 1 period. The expectation
    is that rainfall intensities will not be as high as they were on
    Saturday but the cumulative effect of an additional 1+ inch amounts
    on top of what has already fallen has the potential to produce
    flooding concerns today. The Slight risk area was extended into far
    western South Dakota where MRMS showed 3+ inches having fallen on
    Saturday evening and was susceptible to flooding from even modest
    rainfall amounts.

    Southeast US...
    Also introduced a Slight Risk area over portions of the Southeast
    US where some model agreement has developed...although the
    agreement was far from unanimous. Neither the HREF or RRFS showed
    a strong signal for exceedance of flash flood guidance but showed
    about 20 percent neighborhood probabilities of rainfall exceeding 2
    inches. At the same time...a spaghetti plot of SREF QPF showed
    decent amount of ARW members with QPF at 2 inch and 3 inch amounts.
    That was largely supported by the GEFS. Given the 2 to 2.25 inch
    precipitable water values and the amount of instability in the area
    that could support intense rainfall rates...opted to include a
    Slight Risk at this point.

    Elsewhere...maintained the broad and largely unfocused Marginal
    Risk area in between given the lack of clear forcing mechanism, the
    light flow aloft and the broad pool of instability along and south
    of a quasi-stationary boundary.

    Bann


    Day 2
    Valid 12Z Mon Jun 01 2026 - 12Z Tue Jun 02 2026

    ...THERE IS A MARGINAL RISK OF EXCESSIVE RAINFALL OVER PORTIONS OF
    THE NORTHERN ROCKIES AND PARTS OF THE PLAINS...

    Northern Rockies...
    Introduced a Marginal Risk area in the northern Rockies where moisture/precipitation lingers as a slow moving mid- and upper-
    level system pulls away. The concern is not so much for rainfall
    intensity at this point but for the cumulative effect of the
    additional rain on top of what has fallen in the previous few days.
    The concern is also fairly limited in terms of duration as
    rainfall does come to an end during the middle- to latter-part of the period.

    Western High Plains...
    Also introduced a Marginal Risk area mainly in the western portion
    of Kansas/Nebraska as an axis of low level moisture begins to
    return northward during the day. Placement of the QPF and any
    associated risk of excessive rainfall remains somewhat tenuous.
    Concern is that the instability should be enough that the QPF
    amounts approaching or exceeding 2 inches from the UKMET/NAM and
    GFS would be delivered quickly. A

    Southeast US...
    Portions of the Mid-South/Southeast may also be at-risk for
    Excessive Rainfall, but guidance remains murky on where storms will
    initiate. Given these reasons, the Day 2 ERO remains free of risk
    areas for the time being.

    Mullinax/Bann


    Day 3
    Valid 12Z Tue Jun 02 2026 - 12Z Wed Jun 03 2026

    ...THERE IS A SLIGHT RISK OF EXCESSIVE RAINFALL OVER PORTIONS OF
    NEW MEXICO AND A SMALL PORTION OF WEST TEXAS...

    A plume of Gulf-sourced moisture will be drawn northward into the
    southern Rockies/drifting east over the southern High Plains/west
    Texas to maintain a Slight Risk area for excessive rainfall on
    Tuesday into Tuesday night from portions of New Mexico into west
    Texas. Farther north...warm moist air will advect along a low
    level convergence zone with early June heating that has the
    potential for locally heavy rainfall over portions of the western
    High Plains into the Dakotas.

    Bann
    $$
    --- SBBSecho 3.28-Linux
    * Origin: Capitol City Online (618:250/10)
  • From Mike Powell@618:250/10 to All on Mon Jun 1 09:03:39 2026
    FOUS30 KWBC 010807
    QPFERD

    Excessive Rainfall Discussion
    NWS Weather Prediction Center College Park MD
    407 AM EDT Mon Jun 1 2026

    Day 1
    Valid 12Z Mon Jun 01 2026 - 12Z Tue Jun 02 2026

    ...THERE IS A MARGINAL RISK OF EXCESSIVE RAINFALL OVER PORTIONS OF
    THE NORTHERN ROCKIES, GREAT PLAINS, AND MID-SOUTH...

    ...Northern Rockies...
    A closed mid-level system will continue to slowly move across
    Montana during the period, bringing an additional 1 to 2 inches of
    rainfall. The Marginal Risk for isolated / localized flooding was
    maintained with minimal adjustments based on the 00Z guidance.

    ...Mid-South...
    Early morning MCS across eastern Kansas and Missouri is expected
    to continue to move east/southeast through this morning toward the
    TN Valley and Mid-South. Forward propagation after 12Z should
    overall limit widespread heavy rainfall, but some elements may
    locally train/repeat over the same area bringing a risk of flash
    flooding, particularly early in the period across eastern Missouri.
    While that activity is likely to wane by late morning, additional
    thunderstorms are expected to fire up along remnant outflow
    boundaries to the south and west across Mississippi and Alabama.
    Pockets of 1-2" in a short duration may result in isolated flooding,
    with the overall threat maintained at the Marginal Risk level.

    ...Central Plains...
    Broad upper level forcing across the region along with modest
    southeasterly low level flow will bring isolated to scattered
    diurnally driven convection today across the High Plains that will
    gradually track eastward through south central Nebraska and western
    to central Kansas into this evening and overnight. The Marginal
    Risk was maintained with a few adjustments based on the latest
    model guidance.

    ...West Texas into New Mexico...
    Modest forcing for ascent across the region combined with low level southeasterly flow will bring westward Gulf moisture. Diurnal
    convection is expected across the Davis and Sacramento Mtns. Based
    on the 00Z hi-res models, some of this convection may spread away
    from the terrain, but overall expected to be isolated in coverage
    with a localized flash flood risk today.

    Taylor


    Day 2
    Valid 12Z Tue Jun 02 2026 - 12Z Wed Jun 03 2026

    ...THERE IS A SLIGHT RISK OF EXCESSIVE RAINFALL ACROSS PORTIONS OF
    WEST TEXAS INTO NEW MEXICO...

    ...West Texas into New Mexico...
    By Tuesday, the latest model guidance suggests greater moisture
    will expand westward toward the region (compared to today) with PW
    anomalies approaching 1.5 to 2 std deviations above normal. Another
    round of terrain driven convection is expected that spreads east
    across the area. Overall, pockets of 1 to 2 inches are possible
    with resulting isolated/scattered flash flooding, particularly for
    any sensitive locations such as burn scars and steeper terrain.

    ...Great Plains...
    Large scale forcing for ascent across the High Plains will work
    with an increasing amount of low level moisture to produce several
    clusters of thunderstorms during the period capable of producing
    heavy rainfall - one area of concern is across eastern to central
    Kansas where the latest guidance has pointed toward the potential
    for several repeating clusters of intense rain rates. Some of this
    additional rainfall may fall on areas expected to see heavy
    rainfall today. A second area of concern is the Northern Plains
    where there is likely to be better forcing with the proximity to
    the mid/upper level feature. Here, moisture isn't as high and storm
    motions may be faster, but potential exists for intense rain rates
    and locally heavy rainfall. Both of these areas (Dakotas and
    western/central KS) may need upgrades to Slight Risk if trends
    continue with future model cycles but for now, have maintained the
    Marginal given some of the uncertainty heading into Tuesday.

    ...North Florida through the Gulf Coast...
    A cold front will slowly advance southward across the region during
    the day Tuesday, with copious amounts of moisture pooling along and
    ahead of it. Thunderstorms are likely to develop, particularly
    focused on the Florida Panhandle to northeast Florida where the
    latest guidance points to the potential of 1-3" locally. Localized
    / isolated flash flooding will be possible due to the expected
    intense rain rates and overall slower storm motions.

    Taylor


    Day 3
    Valid 12Z Wed Jun 03 2026 - 12Z Thu Jun 04 2026

    ...THERE IS A SLIGHT RISK OF EXCESSIVE RAINFALL OVER PORTIONS OF WEST TEXAS...

    ...West Texas into New Mexico...
    A greater signal exists for a stronger mid-level shortwave to move
    across the southern High Plains on Wednesday. This feature,
    combined with the continued relatively higher moisture in place,
    should result in robust convection to develop across far eastern
    New Mexico into western Texas, particularly across the TX Panhandle.
    A Slight Risk was maintained for the potential of isolated to
    scattered flash flooding, some of which may fall on similar areas as Tuesday.

    ...Great Plains...
    The active pattern across the Plains is expected again on
    Wednesday with a plume of relatively higher moisture extending from
    Texas all the way north into the Northern Plains. Daytime
    convection is expected to fire up across the Plains and then move east/southeast into the evening/overnight hours. Several organized
    clusters of convection are likely with pockets of locally heavy
    rainfall. For now, a broad Marginal Risk remains in place for
    isolated instances of flash flooding.

    Taylor
    $$
    --- SBBSecho 3.28-Linux
    * Origin: Capitol City Online (618:250/10)
  • From Mike Powell@618:250/10 to All on Tue Jun 2 09:58:50 2026
    FOUS30 KWBC 020809
    QPFERD

    Excessive Rainfall Discussion
    NWS Weather Prediction Center College Park MD
    409 AM EDT Tue Jun 2 2026

    Day 1
    Valid 12Z Tue Jun 02 2026 - 12Z Wed Jun 03 2026

    ...THERE ARE SLIGHT RISKS OF EXCESSIVE RAINFALL ACROSS PORTIONS OF
    WEST TEXAS INTO NEW MEXICO AND NORTH DAKOTA...

    ...Dakotas...
    A mid to upper level system and associated surface front will
    approach the region during the period. Ahead of it, warm moist air
    will expand across the area with the latest guidance showing
    precipitable water values over 1.2" and by afternoon, MUCAPE values
    in excess of 1000 J/kg. Deep convection firing up in the afternoon
    will initially be more discrete but is expected to evolve into
    linear segments as the evening commences with a ramp up late in the
    period possible with the developing low-level jet.

    The 00Z HREF shows the threat for rainfall totals in excess of 3"
    across the Slight Risk area with the greatest potential across
    central to northeastern ND (50-80 percent). Isolated maximum hourly
    rainfall totals of 2 inches will be possible. For these reasons,
    the Slight Risk for flash flooding looks appropriate and no
    significant changes were made for this update.

    ...Eastern New Mexico into West Texas...
    Another day of isolated to scattered thunderstorms across the
    region is expected as moist southeasterly flow expands further
    westward into eastern New Mexico. With cool temperatures aloft
    given the baggy trough in place, this should be sufficient for
    greater coverage of thunderstorms, initially tied to the terrain
    and then moving eastward toward the NM/TX border. Peak hourly
    rainfall totals in excess of 1 inch will be possible across eastern
    NM and total amounts of 1" to locally 3" will be possible. The
    Slight Risk is maintained for the potential of isolated to widely
    scattered flash flooding particularly for sensitive areas like
    burn scars and steeper terrain.

    ...Gulf Coast into South Florida...
    A frontal boundary analyzed early this morning across the Gulf
    Coast is expected to slowly drop southward through the period.
    Along and ahead of this feature, precipitable water values range
    from 1.5" to locally over 2", which is around 1.5 std above normal
    for some locations. The frontal position, combined with a favorable
    upper pattern, will provide the forcing for ascent today. With
    expected instability values exceeding 1500 J/kg (MUCAPE) during
    peak heating, scattered to numerous showers and thunderstorms are likely.

    The latest HREF probabilities show potential for hourly rain
    totals between 1-2" (up to 50 percent probability), peaking during
    the afternoon to early evening hours. Totals of 1-3" are expected
    within the risk area, with isolated totals of 3-5" possible in the strongest/slowest thunderstorms, most likely to occur across
    portions of FL Panhandle and across South Florida. Isolated to
    scattered instances of flash flooding are possible given the
    potential for intense rain rates, particularly over sensitive
    locations like urban corridors.

    Taylor


    Day 2
    Valid 12Z Wed Jun 03 2026 - 12Z Thu Jun 04 2026

    ...THERE IS A SLIGHT RISK OF EXCESSIVE RAINFALL ACROSS WEST TEXAS
    INTO NEW MEXICO...

    ...West Texas into New Mexico...
    Weak troughing aloft and the remaining relatively higher moisture
    in place across the region will likely promote the development of
    isolated to scattered thunderstorms again on Wednesday. The focus
    for the greatest concentration of thunderstorms and rainfall
    totals will shift a bit further east this day, likely along the
    NM/TX border into the TX Panhandle where amounts of 1-2" with
    isolated 3" totals likely. Isolated to scattered instances of flash
    flooding will be possible.

    ...Great Plains...
    An axis of higher moisture will be present ahead of an advancing
    cold front moving across the Northern Plains. Moist unstable air
    ahead of it will promote the development of several clusters of
    thunderstorms capable of producing intense rain rates between
    1-2"/hr. Isolated to scattered flash flooding is anticipated with
    a possible upgrade to a Slight Risk needed for parts of eastern ND
    and far western MN if trends continue for a more concentrated area
    of thunderstorms and heavy rainfall.


    Day 3
    Valid 12Z Thu Jun 04 2026 - 12Z Fri Jun 05 2026

    ...THERE IS A MARGINAL RISK OF EXCESSIVE RAINFALL ACROSS PORTIONS
    OF THE PLAINS, UPPER MIDWEST, AND TEXAS...

    ...Northern Plains into the Upper Midwest...
    Shortwave energy ejects into the Plains during the period with the
    frontal boundary expected to become increasingly west to east
    oriented as it drapes across the Upper Midwest by Thursday. This
    will allow the moisture to pool ahead of it while also creating a
    more favorable setup for training/repeating thunderstorms that are
    expected to develop during the peak heating and continue into the
    overnight hours with the surging low level jet. While there
    remains uncertainty on placement (north solutions versus some that
    are further south), the ingredients appear to be in place for heavy
    rainfall from portions of the Dakotas eastward toward Minnesota.
    For now, a Marginal Risk remains in place but an upgrade to a
    Slight Risk may be needed in future updates if trends continue for
    a training thunderstorm scenario.

    ...Plains to Texas...
    A mid to upper level system slowly moving east out of western
    Mexico will approach the region during the period. As it does so,
    it will continue to pull into the area copious amounts of Gulf
    moisture. This will bring additional rounds of thunderstorms to the
    area, some of which will be locally heavy given the PWs in place
    and potential for repeating rounds. For now, will keep a Marginal
    Risk in place, but if greater organization of storms or confidence
    on specific areas rises, a Slight Risk may be needed for portions
    of western to central Texas with future updates.

    Taylor
    $$
    --- SBBSecho 3.28-Linux
    * Origin: Capitol City Online (618:250/10)
  • From Mike Powell@618:250/10 to All on Wed Jun 3 09:04:22 2026
    FOUS30 KWBC 030801
    QPFERD

    Excessive Rainfall Discussion
    NWS Weather Prediction Center College Park MD
    401 AM EDT Wed Jun 3 2026

    Day 1
    Valid 12Z Wed Jun 03 2026 - 12Z Thu Jun 04 2026

    ...THERE ARE SLIGHT RISKS OF EXCESSIVE RAINFALL ACROSS PORTIONS OF
    THE NORTHERN PLAINS AND WEST TEXAS INTO EASTERN NEW MEXICO...

    ...Northern Plains...
    Multiple areas of convection producing heavy rainfall and intense
    rainfall are expected across portions of the eastern Dakotas into
    far western Minnesota during the period. This activity is tied to
    an advancing cold front with an axis of anomalous moisture along
    and ahead of it. While the setup isn't the most favorable for training/backbuilding and generally favors more progressive storm
    motions, the ingredients do support the latest HREF probabilities
    for isolated totals in the 3-5" range. The Slight Risk was
    minimally adjusted to the latest trends.

    ...Texas into Oklahoma...
    A surface boundary in the vicinity of the area along with a feed
    of Gulf moisture from the southeast will continue the unsettled
    weather pattern. Convection is likely to be ongoing at the start of
    the period across far eastern NM into western TX, capable of
    producing locally heavy rainfall and rain rates between 1-2"/hr.
    This activity may then subside by mid day. Convection is then
    expected to blossom further to the northeast across the TX
    Panhandle and west-central Oklahoma. The Slight Risk in that area
    looks good and lines up well with the latest HREF probabilities
    for 3 inches (50-70 percent) and 5 inches (25 percent).

    ...South Florida and the Keys...
    Approaching frontal boundary and tropical moisture in place will
    contribute to another day of higher coverage and intensity of
    thunderstorms across portions of South Florida urban corridor. HREF probabilities are elevated for localized 3-5" totals (along with
    hourly rain totals locally between 2-3") where thunderstorms
    persist/repeat, so a Marginal Risk has been maintained. There is
    some signal that the intense rain rates and heavy rainfall may
    approach the entirety of the Keys, so have opted to expand the
    Marginal through Key West.

    Taylor


    Day 2
    Valid 12Z Thu Jun 04 2026 - 12Z Fri Jun 05 2026

    ...THERE ARE MARGINAL RISKS OF EXCESSIVE RAINFALL ACROSS THE
    PLAINS TO THE UPPER MIDWEST AND SOUTH FLORIDA ...

    ...Plains to Upper Midwest...
    The cold front is expected to set up across Minnesota into the
    Plains during the period, acting as the focus for organized
    convection. A ramp up in the low-level jet late in the period will
    likely be the primary concern for training/repeating rounds of
    heavy rainfall as daytime convection should be mainly progressive
    and more discrete in nature. The deterministic guidance remains
    disperse and ensemble probabilities low to provide confidence for
    any upgrade to Slight Risk at this time, but areas from southwest
    Minnesota into portions of Iowa and eastern South Dakota are of
    concern. For now, the Marginal Risk was maintained and adjusted to
    the latest trends, trimming some from the western to northern boundary.

    Further south into the Plains and Texas, the continued moist
    southeasterly flow and approaching mid level system out of Mexico
    will bring a greater coverage of thunderstorms and the threat of
    locally heavy rainfall. Overall organization of the convection is
    expected to be on the lower side, but the PW anomalies support
    potential for locally intense rain rates and the Marginal Risk.

    ...South Florida...
    Frontal boundary stalling in the vicinity of the area will remain
    the focus for scattered to numerous showers and thunderstorms
    capable of producing intense rain rates and locally heavy rainfall
    over the highly urbanized corridor. The risk for Thursday shifts a
    bit further south across South Florida, mainly centering across the
    Miami metro.

    Taylor


    Day 3
    Valid 12Z Fri Jun 05 2026 - 12Z Sat Jun 06 2026

    ...THERE IS A MARGINAL RISK OF EXCESSIVE RAINFALL ACROSS PORTIONS
    OF THE PLAINS, UPPER MIDWEST, TEXAS, AND GULF COAST...

    ...Upper Midwest...
    Low pressure moving across the region with its associated cold
    front will be the focus for thunderstorm development Friday into
    Friday night with southwesterly flow bringing in an axis of
    relatively higher moisture. Aspects of this setup will favor
    some training/repeating thunderstorms but the overall motion will
    probably lean more progressive. If the front ends up more west to
    east oriented and allows for a better setup for training, portions
    of the area could need an upgrade to a Slight, but confidence on
    that is too low at this point.

    ...Texas into Gulf Coast...
    The mid/upper level feature over Mexico moves into Texas during
    this period, continuing another day of generally unsettled weather
    and scattered to numerous showers and thunderstorms. If deeper
    instability can materialized, pockets of locally heavy rainfall
    will be possible due to the intense rain rates. Right now, the
    latest deterministic guidance and ensemble probabilities point
    toward central to south TX with greater potential.

    Along coastal Louisiana, a surface trough interacting with the
    higher moisture in place will bring a higher coverage of
    thunderstorms with the potential for intense rain rates and
    localized heavy rainfall.

    Taylor
    $$
    --- SBBSecho 3.28-Linux
    * Origin: Capitol City Online (618:250/10)
  • From Mike Powell@618:250/10 to All on Thu Jun 4 08:22:43 2026
    FOUS30 KWBC 040830
    QPFERD

    Excessive Rainfall Discussion
    NWS Weather Prediction Center College Park MD
    430 AM EDT Thu Jun 4 2026

    Day 1
    Valid 12Z Thu Jun 04 2026 - 12Z Fri Jun 05 2026

    ...THERE IS A SLIGHT RISK OF EXCESSIVE RAINFALL OVER A PORTION OF
    THE UPPER MIDWEST...

    Circulation around a broad area of high pressure over the
    Northeast US and the Mid-Atlantic Region will keep an easterly flow
    of deep moisture over Florida and and anticyclonic flow from the
    Texas and Louisiana Gulf coast that becomes southwesterly from
    parts of the Central Plains/Upper Midwest through much of the
    period. An upper low over northern Mexico will help draw some of
    that moisture westward to support the risk of locally heavy
    rainfall there.

    ...Gulf Coast to Upper Midwest/Northern Plains...
    With a persistent fetch of an airmass from the Gulf Coast region
    into the Upper Midwest...precipitable water values increase
    throughout the day...exceeding 2 inches along the Texas Gulf coast
    to the ARKLATEX while increasing to 1.5 inches or more in a plume
    extending into parts of Minnesota and Wisconsin. The highest
    probability of heaviest rain was shown in both the operational
    models and the ensembles across parts of Iowa into portions of
    nearby Nebraska and Kansas as mid level height falls make their way
    out of the High Plains and as surface pressures fall. Rainfall
    rates of 1-2 inches per hour are possible. The 00Z runs of the HREF
    and the RRFS show neighborhood probabilities of 10 to 20 percent
    occurrence for 2 inch amounts in 3 hours for the 24 hour period
    ending at 12Z Friday morning. Those rates could be enough to
    overcome initially dry soils in parts of the area as well as be
    problematic in urban areas.

    Elsewhere along that corridor...there is sufficient CAPE to drive
    locally intense downpours from any convection that forms. The big
    problem is the relatively weak shortwave energy within the flow
    will be difficult to time with much lead-time. As such...left the
    Marginal Risk area pretty much in place with the expectation that
    some area may well stay rain-free.

    ...West Texas to Eastern New Mexico...

    An upper level system over Mexico will help draw some of the deeper
    Gulf moisture westward...keeping a risk of locally heavy rainfall
    and isolated instances of flash flooding. As previously
    mentioned...the overall organization of the convection is expected
    to be on the lower side, but the precipitable water anomalies and
    the subtle increase in the upper level difluence near the
    international border support potential for locally intense rain
    rates and the Marginal Risk.

    ...South Florida...
    Frontal boundary stalling in the vicinity of the area will remain
    the focus for scattered to numerous showers and thunderstorms
    capable of producing intense rain rates and locally heavy rainfall
    over the highly urbanized corridor. The risk shifts a bit farther
    south across South Florida compared with yesterday...mainly
    centering across the Miami metro.

    Bann


    Day 2
    Valid 12Z Fri Jun 05 2026 - 12Z Sat Jun 06 2026

    ...THERE IS A SLIGHT RISK OF EXCESSIVE RAINFALL ACROSS PORTIONS OF
    THE UPPER MIDWEST/NORTHERN PLAINS ON FRIDAY...

    ...21Z Outlook Update...
    The ongoing forecast remainder largely on track. The main change
    was the introduction of a Slight Risk across portions of Iowa to
    parts of nearby Wisconsin and Illinois as areas of moderate to
    heavy rainfall lingers in the area. Elsewhere...there were only
    minimal changes needed to the Marginal Risk areas across the
    central Gulf Coast to New Mexico...southern Louisiana and the
    southern Florida peninsula.

    Upper Midwest...
    Additional scattered thunderstorm activity is expected once again
    ahead of a front making its way from Iowa into Wisconsin and
    vicinity, spreading 1-2 inches of rain with local amounts reaching
    4 inches. Storms in that area should be progressive in nature due
    to 20-30 knot mid/upper level flow, though localized backbuilding
    and mergers may increase totals locally.

    The Marginal Risk surrounding the Slight Risk was largely
    unchanged...although some of the territory was removed from the
    northern part of Michigan now that timing of the boundary and low
    level moisture fields have become handled better by the
    models/ensembles.

    Texas into New Mexico...
    Weak mid/upper troughing across the southern Rockies and Texas
    will promote another round of thunderstorm activity across a large
    part of Texas and southern New Mexico, with attendant flash
    flooding expected due to slow storm motions and abundant moisture.

    Coastal Louisiana...
    A trough of low pressure interacting with the higher moisture in
    place will bring a higher coverage of thunderstorms with the
    potential for intense rain rates and localized heavy rainfall.
    Spaghetti plots show more ARW core members than NMMB...suggesting
    that there could still be shifts in placement or QPF amounts
    between now and the time the outlook verifies.

    South Florida...
    A stalled frontal boundary over the southern Florida peninsula
    will continue to focus scattered to numerous afternoon and evening
    showers and thunderstorms. Given the instability...intense rain
    rates and locally heavy rainfall over the highly urbanized
    corridor.

    Bann


    Day 3
    Valid 12Z Sat Jun 06 2026 - 12Z Sun Jun 07 2026

    ...THERE IS A MARGINAL RISK OF EXCESSIVE RAINFALL OVER PORTIONS OF
    THE GREAT LAKES/OHIO VALLEY AND ACROSS THE MIDDLE GULF COAST INTO
    THE SOUTHERN PLAINS...

    Great Lakes/Ohio Valley...
    Maintained a Marginal Risk area over portions of Ohio Valley and
    nearby southern Great Lakes as a front become oriented along an
    east to west axis and flow aloft is weakly forced to lift
    isentropically. Maximum areal average rainfall after the start of
    the period at 12Z Saturday generally looks to be little more than
    an inch. The cumulative effect of rainfall on Days 2 and 3
    suggested it was too early to entirely remove the Marginal.

    Texas northward into the Southern Plains...
    Little change in the overall synoptic pattern is expected with
    southerly flow of moisture continuing to be drawn into parts of the
    Southern Plains. Some stronger/better defined shortwave energy
    within the flow aloft will promote yet another round of
    thunderstorm activity across a large part of Texas and southern New
    Mexico and extending as far north as parts of Oklahoma/Arkansas and
    Kansas by late Saturday night/early Sunday morning, with attendant
    flash flooding expected due to slow storm motions and abundant
    moisture.

    Bann
    $$
    --- SBBSecho 3.28-Linux
    * Origin: Capitol City Online (618:250/10)
  • From Mike Powell@618:250/10 to All on Fri Jun 5 09:50:36 2026
    FOUS30 KWBC 050817
    QPFERD

    Excessive Rainfall Discussion
    NWS Weather Prediction Center College Park MD
    417 AM EDT Fri Jun 5 2026

    Day 1
    Valid 12Z Fri Jun 05 2026 - 12Z Sat Jun 06 2026

    ...THERE ARE SLIGHT RISKS OF EXCESSIVE RAINFALL ACROSS PORTIONS OF
    EASTERN NEBRASKA/KANSAS INTO THE MID-MISSISSIPPI VALLEY AS WELL AS
    MUCH OF TEXAS/SOUTHERN OKLAHOMA...

    ...Eastern Nebraska/Kansas to Mid-MS Valley...

    A northern stream shortwave with multiple embedded vort maxes will
    move through the Midwest Friday and provide lift for convection.
    First, convection and potential for flash flooding looks to be
    ongoing as the period begins 12Z Friday morning generally near the Iowa/Missouri and Iowa/Illinois border. This also sends
    precipitation into Wisconsin and Lower Michigan in the morning to
    early afternoon, but ahead of the influx of instability, so this is
    a more Marginal flood threat. The next and likely stronger energy
    in the shortwave, along with a cold front slowly shifting
    southward, will help develop another round of storms beginning in
    the afternoon and likely becoming enhanced in the evening and
    overnight hours. The HREF and its members as well as the REFS show
    this should be centered in southeastern Nebraska and northeastern
    Kansas to southern Iowa, with periods of QPF exceeding FFG (HREF
    and REFS probabilities 20-50% for FFG exceedance). A Slight Risk
    remains reasonable for this activity, but upgrades are not out of
    the question if training looks to overlap with the currently
    ongoing (Thursday night) convection.

    ...Texas to Southern Oklahoma...

    A compact southern stream upper low is forecast to drift from
    northern Mexico across Texas during the Day 1 period. This lifting
    mechanism will be paired with precipitable water anomalies in the
    90-95th percentile in the southern Plains. There is some
    uncertainty in magnitude of instability due to cloud cover, but
    models show CAPE being sufficient at generally 1000-3000 J/kg, with
    the low aloft helping steepen lapse rates. Scattered convection
    that has the ingredients for flash flooding is likely to occur, so
    went with an upgrade to a broad Slight Risk in this issuance. The
    exact focus for the heaviest rain remains somewhat elusive, but
    there is some signal in the CAMs for east-central Texas. Also
    included areas to the west in the Slight, to include some of the
    typically more sensitive/lower FFG areas in the Hill Country to
    Concho Valley and Permian Basin. The Marginal Risk stretches back
    into New Mexico where there are some sensitive areas like burn scars.

    ...Central Gulf Coast...

    A disturbance likely in the form of a trough at low levels is
    forecast to drift slowly toward the central Gulf Coast,
    specifically southeastern Louisiana and southern Mississippi. With
    moisture anomalies over the 90th if not the 95th percentile and
    sufficient instability, intense rain rates could lead to a flooding
    threat in the form of a Marginal Risk. Though typically not a very
    sensitive area to flash flooding, antecedent wet conditions could
    enhance the potential. The back end of the trough could also lead
    to heavy rain in the Florida Keys, with the HREF and REFS
    neighborhood probabilities of reaching over 5 inches of rain
    greater than 60 percent, but considering the possibility the
    heaviest rain could be offshore and how much rain the Keys can
    handle with the sandy soils, held off on any risk area.

    Tate


    Day 2
    Valid 12Z Sat Jun 06 2026 - 12Z Sun Jun 07 2026

    ...THERE IS A SLIGHT RISK OF EXCESSIVE RAINFALL ACROSS PORTIONS OF
    THE SOUTHERN PLAINS TO MISSISSIPPI VALLEY...

    ...Southern Plains/Mississippi Valley...

    The meteorological setup on Saturday across the south-central U.S.
    will be similar to Friday, through with the compact upper low
    gradually tracking north across the southern half of the Plains.
    The continued enhanced moisture and instability will yield an
    environment favorable for convection with intense rain rates
    causing flash flooding concerns. Areas farther north into Oklahoma
    should see stronger forcing, while the low level jet could be
    maximized farther south into Texas. Thus covered all this area with
    a Slight Risk. REFS probabilities (which extend through the Day 2
    period) show scattered instances of QPF potentially exceeding FFG.
    Smaller scale boundaries leftover from thunderstorms on previous
    days could provide areas of focus that would likely be unclear
    before the near term.

    ...Central Gulf Coast...

    By Saturday the surface/low level trough mentioned in the Day 1
    discussion should reach the central Gulf Coast during the day, and
    produce heavier QPF on land compared to Friday. Once again,
    antecedent conditions in the region are not typically sensitive,
    but are wetter than normal. REFS probabilities of exceeding FFG are
    20-40% in southeast Louisiana, so will continue to monitor if slow storms/training are likely to cause more Slight Risk level impacts
    and need an upgrade.

    ...Ohio Valley...

    The northern stream shortwave is forecast to push through the Great
    Lakes/Ohio Valley and Northeast on Saturday, with a frontal system
    ahead of it. The front should lay west to east across the Ohio
    Valley, so scattered storms could train and cause isolated flash
    flooding. The Northeast can also expect some convection, but likely
    progressive enough to limit flash flood potential to below a
    Marginal. In this ERO issuance, connected the Plains and Ohio
    Valley Marginal Risks together. There is some potential for storms
    back into northern Missouri and vicinity, which could be very wet
    after multiple rounds of convection, so wanted to cover that area.

    Tate


    Day 3
    Valid 12Z Sun Jun 07 2026 - 12Z Mon Jun 08 2026

    ...THERE IS A SLIGHT RISK OF EXCESSIVE RAINFALL ACROSS PORTIONS OF
    THE SOUTHERN/CENTRAL PLAINS TO LOWER/MIDDLE MISSISSIPPI VALLEY...

    Into Sunday, southern stream energy will continue to push north
    through the central/northern Plains and Midwest while opening up
    into a trough. This will once again provide forcing for
    thunderstorms in the Plains and Mississippi Valley. A low level jet
    of 30-40 kt should bring instability and moisture into the region.
    The best overlap of ingredients for flash flooding, supported by
    GEFS/ECens probabilities for over an inch of rain, will likely be
    centered over Missouri south into Arkansas and west into eastern
    parts of Kansas and Oklahoma, so this is where the Slight Risk is
    drawn for Day 3. Some convection could linger farther south toward
    the Gulf Coast, which the Marginal covers. By Sunday night, a
    northern stream trough with a strong vort max is forecast to push
    into the northern High Plains, bringing enhanced QPF ahead of it
    for a Marginal Risk stretching through portions of the Dakotas and
    western Minnesota.

    Tate
    $$
    --- SBBSecho 3.28-Linux
    * Origin: Capitol City Online (618:250/10)
  • From Mike Powell@618:250/10 to All on Sat Jun 6 10:03:30 2026
    FOUS30 KWBC 060800
    QPFERD

    Excessive Rainfall Discussion
    NWS Weather Prediction Center College Park MD
    400 AM EDT Sat Jun 6 2026

    Day 1
    Valid 12Z Sat Jun 06 2026 - 12Z Sun Jun 07 2026

    ...THERE ARE SLIGHT RISKS OF EXCESSIVE RAINFALL FOR PORTIONS OF THE
    SOUTHERN PLAINS, OHIO VALLEY, UPPER TEXAS COAST, AND CENTRAL GULF COAST...

    ...Southern Plains...

    A plume of deep tropical moisture will surge northward across the
    Southern Plains on Saturday. The low level jet advecting this
    moisture north will run into an area of enhanced lift due to a
    nearby upper level shortwave, which will be lifting northeast to
    rejoin the jet. The result will be a series of rounds of storms
    moving north-northeast across portions of north Texas, eastern
    Oklahoma and western Arkansas. Highly efficient warm rain processes
    will dominate due to the present of such abundant amounts of
    moisture, with PWATs close to 2 inches. For eastern
    Oklahoma/western Arkansas, the rain will persist for much of the
    day in the form of training lines of storms. Back into Texas, the
    threat will be mostly overnight tonight due to persistent storms
    associated with an MCS that will drift east across far north Texas
    and southern Oklahoma. An internal higher-end Slight was introduced
    from southwest of the Metroplex through it, and continuing into
    much of eastern Oklahoma and western Arkansas for the combination
    of two areas of persistent heavy rain. Overall changes from
    inherited were minimal.

    ...Ohio Valley...

    A very-slow moving cold front drifting south across the
    Midwest/Ohio Valley on Saturday will be the animus for multiple
    rounds of storms which will track east-southeast from Indiana east
    to the central Appalachians. A new Slight Risk area was introduced
    with this update. In the upper levels, a shortwave may help the
    storms become stronger for the first part of the period before
    shifting off to the east. The front will form the leading nose of a
    plume of deep Gulf moisture tracking northward up the Mississippi
    Valley. The front will "shear" the moisture eastward in a narrow
    corridor, along which the storms will form and move. Stronger and
    more persistent storms from Indiana to western Ohio will become
    somewhat less strong and less organized into the Mountains of
    western Pennsylvania and West Virginia, but those areas will have
    lower FFG thresholds, allowing the two areas to combine into one
    Slight Risk area for somewhat different reasons. Uplift along the
    western face of the Appalachians may also locally enhance rainfall rates.

    ...Upper Texas Coast...

    In coordination with HGX/Houston, TX forecast office, a Slight Risk
    upgrade was introduced with this update. Extreme amounts of
    moisture will be in place throughout the atmosphere of southeast
    Texas Saturday afternoon. PWATs between 2 and 2.25 inches are 3
    sigma above normal for this time of year, an impressive threshold
    to meet for June. With peak heating this afternoon, scattered
    showers and thunderstorms are expected to form, likely 20-50 miles
    inland from the coast. Cold pools from Friday's storms and new ones
    from the storms that form Saturday afternoon will likely drive new
    storm development along the I-10 corridor from southwest of Houston
    to the TX/LA border near Beaumont. With plenty of new moisture
    streaming north off the Gulf, the storms will have no trouble
    reforming and training over the same areas for the duration of the
    long afternoon. Nightfall should end the storms in the area due to
    lack of other forcing and the loss of instability. Friday's storms
    have knocked down FFGs in this region significantly, and with good
    capability of efficient warm rain processes, urban concerns in
    Houston, and slow storm movement were all reasons contributing to
    the Slight Risk upgrade.

    ...Central Gulf Coast...

    Few changes were needed to the Slight Risk area from New Orleans
    east to Pensacola. A strong front is in place across the eastern
    Gulf, characterized by very dry air to its east, rather than any
    significant temperature gradient. The dry air is 2 sigma below
    normal over portions of central Florida...under 1 inch PWATs.
    Meanwhile to the west from Louisiana through Texas, an abnormally
    moist air mass will be streaming north to the west of the high
    pressure area characterized by the dry air. Over much of Louisiana,
    PWATs will be over 2.25 inches or 3 sigma above normal. The front
    makes up the gradient between these extremely contrasting air
    masses. Through the day, the front will push east as the moist air
    mass gradually gains ground. However, the front will be the forcing
    along which numerous showers and thunderstorms pushing north out of
    the Gulf will form along. The front will be slow to move, allowing
    repeating rounds of storms to impact the central Gulf Coast. FFGs
    are high, about 4 inches/hour, but the repeating rounds of storms
    should rather quickly bring those numbers down, allowing for widely
    scattered instances of flash flooding to develop where the rains
    are most persistent by late afternoon. Nightfall should see a
    decrease in shower and storm activity, ending the flooding threat.

    Wegman


    Day 2
    Valid 12Z Sun Jun 07 2026 - 12Z Mon Jun 08 2026

    ...THERE IS A SLIGHT RISK OF EXCESSIVE RAINFALL FOR MUCH OF THE
    MID-MISSISSIPPI VALLEY, OZARKS, AND THE WESTERN TENNESSEE VALLEY...

    A pair of forcings will work cause renewed rounds of showers and
    storms across much of the Mississippi Valley on Sunday into Sunday
    night. A slow moving but still potent upper level low will track
    northeastward up the Plains and into the Midwest by late Sunday
    night. Meanwhile a strong front oriented north-south will allow for
    shower and thunderstorm development further east across portions of
    the South. For the Mid-Mississippi Valley and Ozarks, the shortwave
    will be the primary forcing. Deep tropical moisture characterized
    by PWATs on either side of 2 inches will advect northward up the
    Mississippi Valley. The shortwave will provide the forcing for
    storms to form, along with the topography of the Ozarks. Many of
    these areas, especially from far eastern Oklahoma, northwestern
    Arkansas, and southwest Missouri have seen repeated rounds of heavy
    rain in recent days, so FFGs are lower in this area. Thus, a
    higher-end Slight was introduced for this area depicting an even
    greater threat for flash flooding, as the topography of the Ozarks
    works to increase the severity of any flooding. FFGs are also lower
    from northern Missouri into Iowa. Storms forming in these areas
    will be closer to the nose of the low level jet, though the upper
    level shortwave should still be the primary forcing.

    The Slight Risk area was expanded north up the Mississippi Valley
    into southern and eastern Iowa and western Illinois with this update.

    For portions of the western Tennessee Valley, including western
    Tennessee far northeastern Mississippi, and especially northern
    Alabama, the aforementioned north-south oriented front will be the
    primary forcing for the first half of the day. The front will more
    rapidly retreat east across Georgia by Sunday night, leaving any
    forcing to weak upper level shortwaves. Thus, most of the storms
    will be during the afternoon and evening during peak heating and
    when the front is closer. FFGs are lower across northern Alabama
    from recent heavy rainfall, around 2.5 in/hour, which due to PWATs
    occasionally over 2 inches, should be easily attainable by the
    strongest storms expected Sunday afternoon. Thus, the Slight Risk
    was expanded southeast for these reasons.

    Wegman


    Day 3
    Valid 12Z Mon Jun 08 2026 - 12Z Tue Jun 09 2026

    ...THERE IS A SLIGHT RISK OF EXCESSIVE RAINFALL FOR PORTIONS OF THE MID-MISSISSIPPI, LOWER OHIO, AND WESTERN TENNESSEE VALLEYS...

    On Monday, the excessive rainfall risk translates a bit further
    north and east into the Mid-Mississippi, lower Ohio, and western
    Tennessee Valleys. A strong front over the Great Lakes will retreat northeastward as the plume of anomalously deep moisture from the
    Gulf surges northeastward to replace the drier air mass in place
    over the Northeast. A slow-moving negatively tilted trough will
    also promote upper divergence and lift throughout the atmosphere
    over the Slight Risk area throughout the period. PWATs around 2
    inches will be 3 sigma above normal for this time of year across
    the region, so many of the storms that form will consist of highly
    efficient warm rain processes, which will promote heavy rainfall.
    FFGs across the region will average around 2-2.5 inches, which will
    be easily overcome by many of the strongest cells, so long as their
    forward speed is kept in check. The Slight Risk area was nudged
    west over more of southeastern Missouri with this update, adjusted
    for expected heavy rainfall and likely lower FFGs in this region
    from the Day 2/Sunday period.

    Wegman
    $$
    --- SBBSecho 3.28-Linux
    * Origin: Capitol City Online (618:250/10)
  • From Mike Powell@618:250/10 to All on Sun Jun 7 09:10:22 2026
    FOUS30 KWBC 070816
    QPFERD

    Excessive Rainfall Discussion
    NWS Weather Prediction Center College Park MD
    416 AM EDT Sun Jun 7 2026

    Day 1
    Valid 12Z Sun Jun 07 2026 - 12Z Mon Jun 08 2026

    ...THERE IS A SLIGHT RISK OF EXCESSIVE RAINFALL FOR MUCH OF THE
    MID-MISSISSIPPI VALLEY, OZARKS, AND WESTERN TENNESSEE VALLEY...

    Numerous thunderstorms are expected to form this afternoon into
    tonight over a broad area spanning across the Great Plains and
    Mississippi, Ohio, and Tennessee Valleys. Three primary forcings
    will trigger storms: an upper level shortwave moving north across
    the central Plains, Mid-Mississippi Valley, and Upper Midwest, a
    strengthening cyclone emerging in the northern/central Plains, and
    a quasi-stationary frontal boundary draped across the Mid-
    Mississippi and Ohio Valleys. These features will interact with a
    moist, unstable air mass that will support efficient rainfall
    processes that could lead to heavy rainfall. Deep, moist southerly
    flow has primed the atmosphere across the Plains and Mississippi
    Valley, increasing PWAT values to around 2 inches (2-2.5 standard
    deviations above normal for this time of year). Hi-res CAM guidance
    suggests rainfall rates of 2-4 inches per hour will be possible in
    thunderstorm cells across the Mid-Mississippi Valley and portions
    of the Ozarks and western Tennessee Valley, which would exceed
    current flash flood guidance and result in scattered instances of
    flash flooding within the Slight Risk area. Areas from eastern
    Oklahoma into western Arkansas and east-central Illinois into west-
    central Indiana may be more susceptible to flash flooding after
    rainfall yesterday left soils thoroughly saturated. Heavy rain will
    likely result in locally high rainfall totals, potentially
    reaching 5-7 inches for some locations within the Slight Risk area.

    Locally heavy rainfall will also extend along the quasi-stationary
    frontal boundary into Ohio Valley. Storms forming along the
    boundary will have the potential to produce rainfall rates over 2
    inches per hour, and storm motion will be fairly slow. However,
    convection should be more isolated over the Ohio Valley portion of
    the front, resulting in only a Marginal Risk. Stronger convection
    will also be possible in the vicinity of the low pressure system
    over the northern Plains, but storms will be much more progressive
    in this region, which will limit heavy rainfall potential and the
    risk of flash flooding. The Marginal Risk area extends across the
    northern Plains to account for isolated flash flood potential with
    stronger thunderstorms that may form.

    Dolan


    Day 2
    Valid 12Z Mon Jun 08 2026 - 12Z Tue Jun 09 2026

    ...THERE IS A SLIGHT RISK OF EXCESSIVE RAINFALL FOR PORTIONS OF THE MID-MISSISSIPPI, LOWER OHIO, AND TENNESSEE VALLEYS...

    On Monday, the northern stream cyclone will move north into
    Canada, which will lift the previously stationary frontal boundary
    north across the Upper Midwest and Great Lakes as a warm front and
    push the tail end of the front south into the Carolinas. Heavy
    rainfall potential will be focused in the warm sector of the system
    over the Mid-Mississippi, lower Ohio, and Tennessee Valleys where
    a very moist and unstable air mass will still be in place. A
    splitting upper level shortwave will push some energy across these
    regions, which will support a broad area of widespread/numerous
    thunderstorms. With weakening steering flow, storm motions are
    expected to become very slow, which will heighten the threat of
    flash flooding. The RRFS shows modest probabilities (20-40%) of
    hourly rainfall rates exceeding 2 inches per hour for several hours
    across the Slight Risk area. Some of these areas will also receive
    heavy rainfall during the day 1 period, which may increase the
    risk of flash flooding if areas are impacted by additional storms
    with heavy rainfall on Monday.

    Outside of the Slight Risk area, a broad Marginal Risk area extends
    into the Upper Midwest and central Plains. Anomalous moisture will
    surge north behind the lifting warm front, which will support
    locally heavy rainfall that may lead to isolated instances of flash
    flooding for the western Great Lakes states. Models have also
    started consistently showing a potential MCS forming underneath a
    potent upper level shortwave moving quickly east across the central
    Plains on Monday evening. Though this feature would likely be
    progressive, it could have the potential to produce heavy rainfall
    and isolated flash flooding. There is still some uncertainty
    regarding the location of this feature, resulting in a broad
    Marginal Risk area that will likely be narrowed down over the next
    few forecast cycles.

    Dolan


    Day 3
    Valid 12Z Tue Jun 09 2026 - 12Z Wed Jun 10 2026

    ...THERE IS A MARGINAL RISK OF EXCESSIVE RAINFALL FOR PORTIONS OF
    THE UPPER MIDWEST AND OHIO AND TENNESSEE VALLEYS...

    On Tuesday, an upper level trough will move across the
    northwestern U.S. and support cyclogenesis over the northern
    Plains. A wave of convection is expected to form ahead of the
    developing cyclone, bringing thunderstorms to much of the Upper
    Midwest. A moist and unstable air mass will be in place across the
    Upper Midwest after a warm front lifts north on Monday, which will
    support heavy rainfall in thunderstorms. Flash flood potential
    should be limited by the progressive nature of this system, but
    locally heavy rainfall could still lead to isolated instances of
    flash flooding, especially where soils will be moistened from
    rainfall expected on Sunday and Monday. A Marginal Risk area seems
    sufficient to cover the flash flood threat at this time.

    Another Marginal Risk area is in place for much of the Ohio and
    Tennessee Valleys and portions of Michigan where a slow moving
    frontal boundary will linger through Tuesday. This frontal boundary
    will provide modest lift/support for scattered convection across
    these regions. An anomalously moist air mass will still be in
    place, which should be enough to support locally heavy rain in some
    stronger storms and may lead to isolated instances of flash
    flooding. The flash flood threat will be significantly lower for
    these regions than on Monday with much weaker synoptic support.

    Dolan
    $$
    --- SBBSecho 3.28-Linux
    * Origin: Capitol City Online (618:250/10)
  • From Mike Powell@618:250/10 to All on Mon Jun 8 09:58:55 2026
    FOUS30 KWBC 080819
    QPFERD

    Excessive Rainfall Discussion
    NWS Weather Prediction Center College Park MD
    419 AM EDT Mon Jun 8 2026

    Day 1
    Valid 12Z Mon Jun 08 2026 - 12Z Tue Jun 09 2026

    ...THERE IS A MODERATE RISK OF EXCESSIVE RAINFALL FOR PORTIONS OF
    THE OZARKS...

    Convection will be ongoing at the start of the period across the
    Ozarks where a low level jet ahead of a mid-level vortex/wave will
    create favorable convective conditions that will likely lead to
    impactful flash flooding, especially near steep terrain. During the
    early morning hours, hi-res CAMs are showing rainfall totals as
    high as 5-8 inches for portions of southeastern Kansas,
    northeastern Oklahoma, southwestern Missouri, and northwestern
    Arkansas where slow, back-building thunderstorms are expected. An
    anomalously moist and unstable air mass is already in place across
    the central U.S., which will support deep convection with highly
    efficient rainfall rates (rates of 2-3 inches per hour are already
    being observed). This region was incorporated in a special update
    Moderate Risk area overnight, and the Moderate Risk will continue
    into the beginning of the Day 1 period this morning. Convection
    should wane and shift southeast later this morning into this
    afternoon as the system becomes dominated by the outflow.

    The broader Slight Risk area includes much of the Middle
    Mississippi and Tennessee Valleys where widespread showers and
    thunderstorms are expected in the warm sector of a northern stream
    cyclone today. Much of the convective activity will be driven by
    mesoscale boundaries and remnant MCV activity continuing from the
    overnight period, which will result in variability of the QPE
    across the warm sector. Some convection may be more focused along a quasi-stationary frontal boundary draped over the Tennessee Valley
    and southern Appalachians. Convection will be enhanced by a
    leading upper level shortwave with embedded MCV activity that will
    push east across these regions, and the environment will be
    extremely supportive of heavy rainfall with high moisture (PWAT
    values around 2 inches) and high instability (MUCAPE greater than
    3000 J/kg). Storms are expected to be slow moving due to a lack of
    steering flow, which will allow for locally high rainfall totals.
    Latest CAM guidance suggests rainfall rates up to 2-3 inches per
    hour and totals up to 5-8 inches will be possible over portions of
    the Middle Mississippi and Tennessee Valleys. HREF neighborhood
    probabilities show the highest chances of exceeding 5 inches of
    rainfall in 24 hours (25-45%) will be over an area from southern
    Illinois and Indiana through western Kentucky and Tennessee. These
    areas can expect impacts on the higher end of the Slight Risk
    category. Some of the areas within the Slight Risk received heavy
    rainfall on Sunday, which may increase the risk of flash flooding
    if areas are impacted by additional storms with heavy rainfall
    today. The Slight Risk areas has also been extended north into
    central Wisconsin and eastern Iowa where slow-moving storms are
    expected to be enhanced by a mid-level low this afternoon.

    Outside of the Slight Risk area, a broad Marginal Risk area extends
    into the Upper Midwest and central Plains where locally heavy
    rainfall may lead to isolated instances of flash flooding. Storms
    across much of the Upper Midwest should be fairly progressive,
    which will limit flash flood potential, but isolated flooding
    concerns will be possible if heavy rainfall impacts any urban
    areas. Models continue to also show a potential MCS forming
    underneath a potent upper level shortwave moving quickly east
    across the central Plains this evening. Though this feature would
    be very progressive, deep convection will have the potential to
    produce heavy rainfall and isolated flash flooding. This shortwave
    may also enhance convection again over the Middle Mississippi
    Valley tonight, and there could be a scenario where a targeted
    Moderate Risk area is needed.

    Dolan


    Day 2
    Valid 12Z Tue Jun 09 2026 - 12Z Wed Jun 10 2026

    ...THERE IS A SLIGHT RISK OF EXCESSIVE RAINFALL FOR PORTIONS OF THE
    NORTHERN PLAINS AND WESTERN KENTUCKY AND TENNESSEE...

    On Tuesday, a potent upper level trough will move across the
    northern Rockies and emerge into the northern Plains. This trough
    will spur cyclogenesis over the northern Plains while a low level
    jet increases moisture and instability ahead of the system. The
    environment will be ideal for supercell development Tuesday
    afternoon, and increasing shear over the region will allow storms
    to evolve into an MCS Tuesday evening into Tuesday night. Deep
    convection within these severe storms will be able to tap into
    moisture in the atmosphere (PWAT values 1.5-2 inches) and create
    very heavy rainfall. The quick nature of the MCS should somewhat
    limit the risk of flash flooding, but intense rainfall rates in
    excess of 2 inches per hour will exceed FFGs and could lead to
    impactful flash flooding, especially in urban areas. A Slight Risk
    area has been introduced for much of central and eastern North
    Dakota and northwestern Minnesota.

    Scattered showers and storms are forecast from the southern
    Appalachians and Tennessee Valley through the Ohio Valley and Great
    Lakes region, which will be supported by an upper level shortwave
    lifting northeast across the Ohio Valley and Great Lakes and a slow
    moving warm front extending south into the Tennessee Valley and
    southern Appalachians. The air mass in place will be anomalously
    moist (PWATs around 2 inches) and sufficiently unstable to support
    locally heavy rainfall. Available hi-res guidance suggests higher
    rainfall totals will be possible across western Kentucky and
    Tennessee where convection will continue from the Day 1 period into
    Tuesday morning. A mid-level shortwave will be enhancing this
    convection and should allow for efficient rainfall rates over 2
    inches per hour. A Slight Risk area has been introduced to cover
    the elevated flash flood threat over western Kentucky and
    Tennessee. Global models have also been showing locally enhanced
    rainfall totals over portions of the Ohio Valley, but there is
    still a significant amount of uncertainty in the location of these
    higher totals. It is possible the Slight Risk area may need to be
    expanded to the northeast as convective details become more clear
    with additional hi-res guidance available later today.

    Dolan


    Day 3
    Valid 12Z Wed Jun 10 2026 - 12Z Thu Jun 11 2026

    ...THERE IS A SLIGHT RISK OF EXCESSIVE RAINFALL FROM EASTERN KANSAS
    INTO NORTHERN MISSOURI AND SOUTHERN IOWA...

    On Wednesday, the northern Plains cyclone will be moving swiftly
    east and pushing a cold front across the Midwest. Showers and
    thunderstorms are expected ahead of and along the frontal boundary
    from the Midwest to the central Plains, which are encompassed by a
    Marginal Risk of excessive rainfall. The tail end of the front will
    likely hang up on the Rockies and flatten out over the central
    Plains, and low pressure is expected to develop over Kansas where a
    dryline will intersect the boundary. Models are showing impressive
    moisture transport ahead of the frontal boundary Wednesday morning
    and a secondary surge Wednesday night as a strong low level jet
    brings increasing moisture and instability into the central Plains.
    This set up will be conducive for heavy rainfall, and global models
    are showing potential for heightened rainfall totals of 2-4 inches
    within the Slight Risk area, which may be underdone given the
    convective limitations of the models. Locally heavy rainfall may
    also be possible over central Wisconsin and could impact areas
    highlighted with a Slight Risk on Day 2, which could warrant an
    additional Slight Risk upgrade. However, there is much more
    uncertainty regarding rainfall totals in Wisconsin, which may be
    limited by the progressive nature of the cold front.

    Dolan
    $$
    --- SBBSecho 3.28-Linux
    * Origin: Capitol City Online (618:250/10)
  • From Mike Powell@618:250/10 to All on Tue Jun 9 08:11:24 2026
    FOUS30 KWBC 090818
    QPFERD

    Excessive Rainfall Discussion
    NWS Weather Prediction Center College Park MD
    418 AM EDT Tue Jun 9 2026

    Day 1
    Valid 12Z Tue Jun 09 2026 - 12Z Wed Jun 10 2026

    ...THERE IS A SLIGHT RISK OF EXCESSIVE RAINFALL FOR PORTIONS OF THE
    NORTHERN PLAINS, OHIO AND TENNESSEE VALLEYS, AND SOUTHERN APPALACHIANS...

    .Northern Plains...
    A potent upper level trough will push across the northern Rockies
    into the Plains today and spur cyclogenesis over the northern
    Plains. Low pressure will strengthen over the region with a cold
    front extending to the southwest and a warm front extending to the
    east. Southerly winds ahead of the trough will direct warm, moist,
    unstable air into the northern Plains, with PWAT values expected to
    exceed 1.5 inches and MUCAPE expected to rise above 3000 J/kg.
    Increasing mid/low level winds on the leading edge of the trough
    will create a highly sheared environment that is conducive for
    supercell development this afternoon. By this evening, an
    intensifying low level jet oriented parallel to the surface cold
    front will support upscale convective growth into a linear MCS.
    Deep convection within supercells and eventually the more organized
    MCS will be able to tap into the atmospheric moisture to produce
    very intense rainfall rates in excess of 2 inches per hour.
    Relatively fast storm motion will be a limiting factor to the flash
    flood risk, but rainfall rates will be enough to overwhelm FFGs
    and cause flash flooding, especially if heavy rain occurs in urban environments. A Slight Risk of excessive rainfall remains in effect
    for the heaviest convective activity expected over central and
    eastern North Dakota and northwestern Minnesota. A broader Marginal
    Risk area extends into the Midwest where convection may focus
    along a surface boundary extending from the northern Plains cyclone tonight.

    .Ohio and Tennessee Valleys and southern Appalachians...
    An upper level trough will lift northeast across the Midwest and
    Great Lakes region today accompanied by a surface low over the
    Great Lakes and a slow-moving warm front extending south into the
    Ohio and Tennessee Valleys. The air mass in place across these
    regions will be anomalously moist with PWAT values around 2 inches,
    2-2.5 standard deviations above normal for this time of year.
    There will also be sufficient synoptic forcing and instability to
    support scattered to potentially widespread convection from the
    Great Lakes to the Interior Southeast. Convection will be ongoing
    at the start of the period and should translate east throughout the
    day as the system progresses. High moisture content in the
    atmosphere will support chances for locally heavy rainfall, and
    more intense rainfall may be possible over the Ohio and Tennessee
    Valleys where convection will be enhanced by a couple quick-moving
    mid-level waves rounding the top of the ridge positioned over the
    Gulf. The first wave will pass over the region early in the period,
    resulting in a burst of more intense convection this morning. The
    second wave will pass over this area tonight into early Wednesday
    morning and will have the potential for back-building storms along
    a surface boundary extending into the lower Ohio Valley from the
    northern Plains cyclone. Hi-res guidance suggests rainfall rates of
    2-3 inches will be possible in stronger cells, and most hi-res
    CAMs are showing a swath of rainfall totals of 3-5 inches, with
    locally higher amounts, across portions of Kentucky and maybe
    southern Indiana as well. The HREF and RRFS are both showing
    relatively high probabilities (50-70% and 40-50% respectively) of
    24 hr totals exceeding 5 inches in this area. Enhanced convection
    will also be possible, but to a lesser extent, under the upper
    waves over Tennessee and in upslope areas of the southern
    Appalachians. Some areas may be more susceptible to heavy rain
    today after recent heavy rains over the past few days. A Slight
    Risk of excessive rainfall covers the area of enhanced convection
    over the Ohio and Tennessee Valleys and southern Appalachians and
    a Marginal Risk area extends north through the Great Lakes.

    Dolan


    Day 2
    Valid 12Z Wed Jun 10 2026 - 12Z Thu Jun 11 2026

    ...THERE IS A SLIGHT RISK OF EXCESSIVE RAINFALL FOR NORTHEASTERN
    KANSAS, SOUTHEASTERN NEBRASKA, NORTHERN MISSOURI, AND SOUTHERN IOWA...

    .Midwest and central Plains...
    On Wednesday, the northern Plains cyclone will move into south-
    central Canada and push a trailing cold front across the Midwest.
    Showers and storms will be ongoing Wednesday morning ahead of the
    system over northern Minnesota, then another round of convection is
    expected across the Midwest and central Plains Wednesday afternoon
    and evening ahead of and along the cold front. Deep southerly flow
    ahead of the system will increase PWAT values to 1.5-2 inches,
    with the higher values focused between northern Missouri and
    southern Wisconsin. Instability should increase through the
    afternoon as daytime heating kicks in, but the best instability
    (3000-4000 J/kg) looks like it will focus from eastern Kansas and
    southeastern Nebraska into northern Missouri and southern Iowa,
    where there is a Slight Risk of excessive rainfall. This area will
    likely experience a period of enhanced convection Wednesday night
    as a frontal wave develops at the intersection of the cold front
    and a dryline. A secondary wave of moisture and instability will
    surge into the central Plains as a low level jet strengthens
    Wednesday night, which should support efficient rainfall rates,
    potentially exceeding 2 inches per hour, that could lead to
    scattered instances of flash flooding. There is still some
    uncertainty regarding rainfall totals within the Slight Risk area.
    If the frontal wave is more progressive, the risk of flash
    flooding may be limited. A broader Marginal Risk area surrounds the
    Slight Risk and extends up through the Midwest where strong
    convection could result in at least isolated instances of flash flooding.

    .Tennessee Valley and southern Appalachians...
    Convection should be ongoing across portions of the Tennessee
    Valley and southern Appalachians at the start of the period. A
    quick-moving upper level wave will round the top of the ridge
    positioned over the Gulf and support a period of enhanced
    convection late Tuesday night into Wednesday morning. Anomalous
    moisture and sufficient instability will be in place to support
    efficient rainfall rates, and slow storm motions will contribute to
    high rainfall totals. There will also be some potential for back-
    building storms along a surface boundary extending from the
    northern Plains/southern Canada cyclone into the Tennessee Valley,
    mainly focusing over Kentucky. Showers and storms will also be
    enhanced by upslope flow along the southern Appalachians.
    Convection should start to weaken Wednesday morning and wane by
    Wednesday afternoon, but there will at least be enough rainfall
    over saturated soils to continue a Marginal Risk of excessive
    rainfall into Wednesday morning.

    .Interior Northeast...
    A Marginal Risk of excessive rainfall was introduced for portions
    of the Interior Northeast. An upper level trough will cross over
    the Great Lakes into southeastern Canada accompanied by a surface
    low pressure system that will bring precipitation chances to much
    of the Northeast. The warm sector of this system will be
    characterized by an anomalously moist air mass with PWAT values up
    to 2 inches. There should be enough moisture and synoptic forcing
    to support locally heavy rainfall in stronger convection near the
    low pressure center over southeastern Canada and the Interior
    Northeast. Rainfall totals and flash flood potential may also be
    increased by terrain and upslope flow Wednesday afternoon.

    Dolan


    Day 3
    Valid 12Z Thu Jun 11 2026 - 12Z Fri Jun 12 2026

    ...THERE IS A SLIGHT RISK OF EXCESSIVE RAINFALL FROM NORTHEASTERN
    MISSOURI THROUGH EASTERN IOWA AND NORTHERN ILLINOIS TO SOUTHERN WISCONSIN...

    The frontal wave that developed over the central Plains Wednesday
    night will progress northeast and intensify as a strong upper
    trough swings into the northern and central Plains Thursday
    morning. A strong low level jet will increase moisture and
    instability across the central Plains Wednesday night, and this air
    mass will expand towards the Upper Midwest as southerly winds surge
    ahead of the surface frontal boundary. A large swath of high PWAT
    values above 2 inches will stretch from the southern Plains to the
    Midwest, which will support a broad area of convection capable of
    producing locally heavy rainfall. A wave of deeper convection will
    accompany the strong frontal wave as it progresses, resulting in
    high rainfall totals over an area from northeastern Missouri
    through eastern Iowa, northern Illinois, and southern Wisconsin.
    These areas are highlighted by a Slight Risk of excessive rainfall
    to account for enhanced convection capable of producing scattered
    instances of flash flooding. A broader Marginal Risk of excessive
    rainfall surrounds the Slight and includes much of the Midwest and
    portions of the central and southern Plains.

    Dolan
    $$
    --- SBBSecho 3.28-Linux
    * Origin: Capitol City Online (618:250/10)
  • From Mike Powell@618:250/10 to All on Wed Jun 10 07:51:26 2026
    FOUS30 KWBC 100813
    QPFERD

    Excessive Rainfall Discussion
    NWS Weather Prediction Center College Park MD
    413 AM EDT Wed Jun 10 2026

    Day 1
    Valid 12Z Wed Jun 10 2026 - 12Z Thu Jun 11 2026

    ...THERE IS A SLIGHT RISK OF EXCESSIVE RAINFALL FOR PORTIONS OF THE
    CENTRAL PLAINS AND MIDWEST...

    .Midwest and Central Plains...
    A strengthening cyclone will be moving northeast into south-
    central Canada and push a cold front across the north-central
    United States, which will trigger scattered showers and
    thunderstorms ahead of and along the front. A warm front will lift
    north ahead of the system, establishing a broad warm sector from
    the central Plains to the Upper Midwest. The warm sector air mass
    will be characterized by anomalously high moisture content, with
    PWAT values rising to 1.75-2.25 inches. Increasing temperatures
    and moisture will also result in increasing instability, with the
    highest MUCAPE (> 3000 J/kg) expected to concentrate over eastern
    Kansas, northern Missouri and eastern Iowa. Storms forming in this
    area will have the potential to produce heavy downpours with
    rainfall rates of 2-3 inches per hour, which would exceed FFG in
    much of this region. Storms forming further north along the front
    will also have the potential to produce locally heavy rainfall as
    well. Instability should be sufficient for deep convection across
    portions of Minnesota, Wisconsin, and Illinois, and convection may
    become more organized this afternoon with increasing shear along
    the frontal boundary.

    There remains some uncertainty regarding where the heaviest
    rainfall totals will be, but the HREF and RRFS generally agree on
    an area of elevated totals from northern Illinois through
    Wisconsin. This area will likely receive some locally heavy
    rainfall this morning from an eastward propagating MCS out ahead of
    the surface frontal boundary, then another wave of convection
    should ignite across the region this afternoon as the front
    approaches. For the central Plains, rainfall totals have generally
    trended downwards over the past 48 hours, most likely due to a more
    progressive frontal boundary that is oriented SW-NE instead of
    W-E, reducing convergence across the region. The synoptic setup
    should become more conducive for heavy rainfall over the central
    Plains late tonight into early Thursday as a frontal wave develops
    along the boundary and triggers an area of enhanced convection.
    Moisture and instability will surge into the central Plains ahead
    of this feature as a low level jet strengthens, which should
    support efficient rainfall rates in excess of 2 inches per hour.
    For these reasons, a Slight Risk of excessive rainfall extends from northeastern Kansas and southeastern Nebraska to Wisconsin and
    northern Illinois with a broader Marginal Risk area across much of
    the east-central Plains and Midwest.

    .Tennessee Valley and southern Appalachians...
    An MCS is currently moving southeast across the Ohio Valley and
    should move across the eastern Tennessee Valley and southern
    Appalachians this morning. Rainfall rates up to 2-3 inches per hour
    have been observed with this system overnight and will remain
    possible as the system moves across eastern Kentucky. Convection
    should weaken as the system is disrupted by the southern
    Appalachians, but upslope flow may enhance rainfall totals over the
    western Carolinas and western Virginia. Models have trended more
    to the northeast with this MCS, resulting in a shift in the
    Marginal Risk area, trimming out central Kentucky and most of
    western Tennessee and expanding into western Virginia. Luckily,
    rainfall from this system should be displaced from where heavy
    rainfall was observed yesterday over central and western Kentucky,
    but locally heavy rainfall may still lead to isolated instances of
    flash flooding.

    .Interior Northeast and Mid-Atlantic...
    A surface low pressure system will track across southeastern
    Canada today and lift a warm front across the Northeast. Upper
    level troughing extending across the Northeast and Mid-Atlantic
    will allow for a region of broad ascent that will support scattered
    showers and thunderstorms. An anomalously moist air mass will push
    into these regions behind the front, increasing PWAT values up to
    around 2 inches (above the climatological 90th percentile), which
    will allow for locally heavy rainfall with rates of 1-2 inches per
    hour. Rainfall may also be enhanced by upslope flow over the
    terrain in the Interior Northeast and central Appalachians. A
    Marginal Risk of excessive rainfall covers portions of the Interior
    Northeast, central Appalachians, Mid-Atlantic where isolated
    instances of flash flooding will be possible.

    .Southwest Florida...
    Convection will ignite as the Atlantic and Gulf sea breezes
    collide this afternoon over Southwest Florida. Southeasterly flow
    will increase PWAT values across the Florida peninsula throughout
    the day today, with the highest values (2.2-2.5 inches) focused
    over South Florida. Given a very moist atmosphere with strong
    convective forcing at the surface, thunderstorms will be able to
    produce heavy rainfall rates. The latest HREF is showing high
    probabilities (50-70%) of rainfall rates exceeding 2 inches per
    hour, and hi-res CAMs suggest rainfall rates of 3-4 inches will be
    possible in deeper convective cells. Rainfall rates this high will
    likely create localized flooding concerns for urban areas in
    Southwest Florida where there is a Marginal Risk of excessive rainfall.

    Dolan


    Day 2
    Valid 12Z Thu Jun 11 2026 - 12Z Fri Jun 12 2026

    ...THERE IS A SLIGHT RISK OF EXCESSIVE RAINFALL FOR PORTIONS OF THE MIDWEST...

    .Southern Plains to Midwest...
    The frontal wave that developed over the central Plains Wednesday
    night will surge northeast and intensify as a strong trough swings
    across the north-central United States. Strong southerly flow ahead
    of this wave will drive an anomalously moist and highly unstable
    air mass into the Midwest that will support enhanced convection
    in the vicinity of the frontal wave. Showers and storms will also
    form along the frontal boundary as it progresses, extending back
    into the southern Plains, but the progressive nature of the front
    should somewhat limit the flash flood potential over the Plains.
    Moisture will pool ahead of the cold front as it surges
    southeastward, creating a swath of high PWAT values of 2-2.5 inches
    from the southern Plains to the Great Lakes that will support high
    rainfall rates in excess of 2 inches per hour. Available CAMs and
    global models show a broad area of heavy rainfall across the
    Midwest, which is encompassed by a Slight Risk of excessive
    rainfall, and the highest rainfall totals are expected to focus
    over eastern Iowa, northern Illinois, and southern Wisconsin. These
    areas will have the highest risk of flash flooding on Thursday,
    especially after heavy rainfall in the Day 1 period. Additional
    heavy rain falling on top of saturated soils will make these areas
    more susceptible to flash flooding, and there could be a scenario
    where a targeted upgrade to a Moderate Risk may be needed. A larger
    Marginal Risk area stretches from the Midwest to the southern
    Plains where heavy rain may lead to isolated instances of flash flooding.

    .Central Appalachians and Northeast...
    An upper level shortwave trough is forecast to move southeast
    over the Ohio Valley, Northeast, central Appalachians, and Mid-
    Atlantic, which will trigger another round of scattered showers and thunderstorms on Thursday. An anomalously warm and moist air mass
    will be in place across these regions, with PWAT values of 1.75-2
    inches, which will support rainfall rates of 1-2 inches per hour.
    The upper level shortwave will result in an increasingly sheared
    environment over the Northeast Thursday afternoon, which will allow
    for some organized convection with higher rainfall rates in excess
    of 2 inches per hour. These storms should move quickly, but
    intense rainfall rates will support a risk of at least isolated
    instances of flash flooding for portions of eastern Pennsylvania,
    northern New Jersey, southern/central New York, and Connecticut
    where a Marginal Risk of excessive rainfall has been introduced.
    Another Marginal Risk area has been introduced over the central
    Appalachians from West Virginia into southwestern Pennsylvania
    where persistent northwesterly upslope flow will support enhanced
    precipitation chances in this area. Soils will be somewhat
    saturated from rainfall expected in the Day 1 period, and isolated
    flooding concerns may continue into Thursday with showers and
    storms capable of producing rainfall rates of 1-2 inches per hour.

    Dolan


    Day 3
    Valid 12Z Fri Jun 12 2026 - 12Z Sat Jun 13 2026

    ...THERE IS A MARGINAL RISK OF EXCESSIVE RAINFALL FROM THE SOUTHERN
    PLAINS TO THE NORTHERN MID-ATLANTIC...

    A low pressure system tracking across Canada will push a cold front
    across the eastern and south-central United States on Friday. As
    the frontal boundary interacts with the anomalously warm and moist
    air mass in place across the South and East, scattered to numerous
    showers and storms are expected to develop. PWAT values around 2
    inches will stretch from the southern Plains to the northern Mid-
    Atlantic, which should support efficient rainfall rates. High shear
    in the vicinity of the upper level trough over the Northeast and
    northern Mid-Atlantic will likely allow for some strong, organized
    convection with the potential to produce heavy downpours. Storm
    motion across the East should be relatively quick given the
    progressive nature of the front, but this will be the third
    consecutive day of active convection for this region, which will
    support a risk of at least isolated flash flooding. The tail end of
    the front will become quasi-stationary over the southern Plains
    with broad southeasterly flow on the southern side of the
    boundary. Warm, moist air will support convection with locally
    heavy rainfall along the front, and convection may be enhanced
    Friday evening as an upper level shortwave moves east across the
    southern Plains. Showers and storms will likely extend west into
    New Mexico where precipitation chances may be enhanced near the
    Guadalupe and Sacramento Mountains. Locally heavy rainfall could
    also pose a flood risk for burn scars in eastern New Mexico. A
    Marginal Risk of excessive rainfall stretches from the southern
    Plains to the northern Mid-Atlantic to cover these threats.

    Dolan


    Day 4 and Day 5
    Valid 12Z Sat Jun 13 2026 - 12Z Mon Jun 15 2026

    ...THERE IS A SLIGHT RISK OF EXCESSIVE RAINFALL ACROSS PORTIONS OF
    THE CENTRAL AND SOUTHERN PLAINS AND MISSISSIPPI VALLEY THIS WEEKEND...

    Active weather is anticipated across the Central/Southern Plains
    and MS valley this weekend as a favorable environment for heavy
    rainfall rates and training convection evolves southward. On
    Saturday, a Slight risk of excessive rainfall continues for
    portions of eastern KS, northeast OK, northwest AR and much of MO.
    A strongly unstable airmass with CAPE locally over 3000 J/kg is
    forecast to overlap with an increasing plume of above average
    moisture. Large scale ascent focused within the right entrance
    region of an upper level jet and amplified by subtle shortwave
    features will interact with a corridor of strong 850mb moisture
    transport. Given the resulting wind profiles, weak Corfidi vectors
    are probable, favoring backbuilding and cell training. This results
    in rather high confidence in some flash flood impacts, although
    some spatial uncertainty persists. For the moment the Slight risk
    area encompasses the region of best clustering in the multi model
    ensemble (GEFS/ECENS/CMCE/AIFS ensemble).

    On Sunday the threat of excessive rainfall shifts southward into
    the Southern Plains and Lower MS Valley, targeting northeast TX,
    central and eastern OK, northern LA, and much of AR. While the
    overall environment remains similar to the previous day, deep
    layer moisture is forecast to increase further, with PW values well
    over the climatological 90th percentile expected. This environment
    will remain supportive of high rainfall rate flash flood impacts,
    although confidence in placement is lower due to some notable model
    spread. The deterministic AIFS and AIGFS represent the farthest
    south solutions, bringing the heaviest rainfall all the way towards
    the TX Gulf Coast. However, traditional global ensemble clustering
    remains further north, and even the AIFS ensemble mean is a bit
    north of its deterministic run. The current Slight risk area
    focused across the ArkLaTex region is where the full ensemble suite
    (AI and physics based) shows the most overlap at this time.

    Chenard
    $$
    --- SBBSecho 3.28-Linux
    * Origin: Capitol City Online (618:250/10)
  • From Mike Powell@618:250/10 to All on Thu Jun 11 08:14:10 2026
    FOUS30 KWBC 110808
    QPFERD

    Excessive Rainfall Discussion
    NWS Weather Prediction Center College Park MD
    408 AM EDT Thu Jun 11 2026

    Day 1
    Valid 12Z Thu Jun 11 2026 - 12Z Fri Jun 12 2026

    ...THERE IS A SLIGHT RISK OF EXCESSIVE RAINFALL FOR PORTIONS OF THE MIDWEST...

    .Midwest to southern Plains...
    Early this morning, a frontal wave developed over the central
    Plains ahead of a strong upper level trough that will lift into the
    Midwest today. This wave of low pressure is forecast to surge
    northeast into the Midwest and be accompanied by an area of
    enhanced convection in the vicinity of the low. A strengthening low
    level jet on the leading edge of this disturbance will bring a
    surge of moisture (PWAT values > 2 inches) and instability (MUCAPE
    3000 J/kg) into the Midwest and create a sheared environment that
    will allow for organized convection with highly efficient rainfall
    rates up to 2-4 inches per hour. A Slight Risk of excessive
    rainfall is in effect for portions of the Midwest where the hi-res
    CAMs are showing the highest rainfall totals. There was some
    consideration of upgrading to a Moderate Risk for portions of Iowa,
    Wisconsin, and Illinois given recent heavy rains and soil
    saturation, but the highest rainfall totals today are forecast to
    be displaced to the north of where the heaviest rain fell on
    Wednesday, which should keep the risk of flash flooding more in
    line with a high-end Slight. On the backside of the frontal wave,
    the cold front will surge southeast across the central and southern
    Plains this afternoon with showers and storms expected to form
    along the front. Given the highly moist and unstable environment on
    the warm side of the boundary, these storms will be capable of
    producing high rainfall rates, but the progressive nature of the
    front should help limit the risk of flash flooding. A Marginal Risk
    area extends back into the southern Plains where locally heavy
    rainfall may lead to isolated instances of flash flooding.

    .Ohio Valley to Mid-Atlantic...
    An upper level shortwave trough is expected to move southeast
    across the Ohio Valley and Mid-Atlantic today, which will provide
    upper level support for the development of scattered showers and
    storms this afternoon. Warm, moist air will be in place across
    these regions, with PWAT values generally ranging from 1.75-2
    inches, which will support rainfall rates of 1-2 inches. Elevated
    instability (>2000 J/kg) should allow for some deeper convective
    cells that will be capable of producing locally heavy rainfall.
    Isolated instances of flash flooding will be possible, especially
    if heavy rain occurs in urban environments, so there is a Marginal
    Risk of excessive rainfall extending from the Ohio Valley to the
    Mid-Atlantic. Northwesterly upslope flow will also result in
    enhanced precipitation totals along the central Appalachians that
    could create isolated flooding concerns in this region as well,
    which is included in the Marginal Risk area.

    .Southwest Florida...
    Southeasterly flow has increased PWAT values above 2 inches across
    Central and South Florida, which will allow for very heavy
    rainfall rates of 2-4 inches per hour in convection along the sea
    breeze boundaries this afternoon. Hi-res CAMs show the Atlantic and
    Gulf sea breezes colliding over Southwest Florida, which could
    result in flash flooding concerns for urban areas. Therefore, there
    is a Marginal Risk of excessive rainfall for urban areas along the
    west coast of the Florida Peninsula from Tampa south.

    Dolan


    Day 2
    Valid 12Z Fri Jun 12 2026 - 12Z Sat Jun 13 2026

    ...THERE IS A MARGINAL RISK OF EXCESSIVE RAINFALL FROM THE SOUTHERN
    PLAINS TO THE NORTHEAST AND FOR CENTRAL AND SOUTHWEST FLORIDA...

    On Friday, an upper level trough will push across the Northeast and
    drive a cold front across the eastern and south-central United
    States. Scattered showers and storms are expected to develop as the
    frontal boundary interacts with the anomalously warm and moist air
    mass, and increased shear in the vicinity of the trough will
    likely support some deeper organized convection in portions of the
    Mid-Atlantic and Northeast. Moisture will pool ahead of the front,
    and PWAT values are forecast to rise above 2 inches from the
    southern Plains to the Northeast, which will allow for efficient
    rainfall rates. Flash flood potential should be somewhat limited by
    the speed of the front; however, locally heavy rainfall may lead
    to isolated instances of flash flooding. Storms over the southern
    Plains will move slower as the frontal boundary becomes quasi-
    stationary, which may result in some areas of higher rainfall
    totals. A mid-level wave is expected to move east across the
    central/southern Plains Friday evening, which should lift the
    frontal boundary north as a warm front and support a wave of
    enhanced convection Friday night. There is still quite a bit of
    uncertainty in where this area of convection will develop, but
    there will likely be some enhanced flash flood potential over
    portions of the central/southern Plains. Further southwest,
    southeasterly flow and increasing moisture will support enhanced
    showers and storms over West Texas and eastern New Mexico, which
    may create flooding concerns in the vicinity of the Guadalupe and
    Sacramento mountains and in burn scar areas. A Marginal Risk of
    excessive rainfall stretches from the southern Plains to the
    Northeast to cover these threats. Elsewhere, heavy rainfall will
    also be possible in Florida where anomalous moisture will reside.
    Convection along the sea breezes will have the potential to produce
    very heavy rainfall that could lead to flooding concerns for urban
    areas in Central and Southwest Florida. A Marginal Risk area has
    been introduced to cover these threats.

    Dolan


    Day 3
    Valid 12Z Sat Jun 13 2026 - 12Z Sun Jun 14 2026

    ...THERE IS A SLIGHT RISK OF EXCESSIVE RAINFALL FOR PORTIONS OF THE
    CENTRAL PLAINS AND MID/LOWER MISSISSIPPI VALLEY...

    On Saturday, several features will come together to support a heavy
    rainfall threat over the central United States. An upper level
    trough will drop south into the central U.S. while several southern
    stream waves move northeast into the Plains ahead of this feature.
    At the surface, a warm front will lift across the south-central
    U.S. while a cold front moves south across the north-central U.S.,
    creating an area of strong convergence from the central Plains to
    the Mid/Lower Mississippi Valley. In addition to strong synoptic
    forcing, a very warm, moist, and unstable air mass will be in place,
    which will support the development of numerous showers and storms
    with efficient rainfall rates. These features should stall for a
    period as they come together, resulting in an area of very heavy
    rainfall. A Slight Risk is in effect where the heaviest rainfall
    totals are expected from the central Plains to the Mid/Lower
    Mississippi Valley. Locally heavy rainfall will also be possible in
    showers and storms forming along the cold front in the Midwest,
    and isolated flash flooding will be a concern, especially after
    heavy rainfall expected on Day 1/Thursday. Locally heavy rainfall
    may also be possible across West Texas and eastern New Mexico where southeasterly flow may support terrain induced precipitation. A
    Marginal Risk of excessive rainfall surrounds the Slight and
    extends from West Texas and eastern New Mexico to the Great Lakes.

    Dolan


    Day 4 and Day 5

    Valid 12Z Sun Jun 14 2026 - 12Z Tue Jun 16 2026

    ...A SLIGHT RISK OF EXCESSIVE RAINFALL EXISTS FOR PORTIONS OF THE
    SOUTHERN PLAINS, LOWER MISSISSIPPI VALLEY, AND THE SOUTHEAST...

    The overnight guidance continued to show a broad, amplifying trough
    prevailing over over much of the eastern two-thirds of the CONUS
    this period. As shortwave energy drops into the base of the
    trough and further amplifies it, the associated frontal boundary
    is expected to push well south into the southern Plains and lower
    Mississippi Valley on Sunday. Increasing southerly flow from the
    western Gulf will support deepening moisture along the front, while
    upper level jet dynamics and mid-level energy provide areas of
    enhanced ascent. Coinciding with the deepest moisture (PWs at or
    above 2 inches) and some of the better forcing, a Slight Risk was
    drawn on Day 4 from southeastern Oklahoma and northeastern Texas
    over to central Mississippi. This is a southward adjustment from
    the previous issuance given the overnight model trends in bringing
    the front farther south.

    Back to the north, low level upslope flow interacting with mid
    level energy dropping into the broader scale trough is expected to
    help initiate storms capable of producing locally heavy amounts
    and isolated flash flooding concerns as far north as the Colorado
    Rockies.

    By Monday, the front is expected to move more slowly to the
    south and east. As it does, moisture will continue to pool along
    the boundary, with both the GFS and ECMWF showing PWs increasing
    to over 2.25 inches (more than 2.5 std dev above normal) from South
    Texas to southern Alabama. Given the potential for highly-
    efficient, training showers and thunderstorms, heavy amounts and
    flash flooding will be a likely concern across this area. A Slight
    Risk was drawn where the latest guidance showed the greater
    overlap between the deeper moisture and better forcing. Will
    continue to monitor this area for potential upgrades, especially if
    the model signal for heavy amounts continues to increase or show
    successive days of heavy rainfall across the same areas.

    Pereira
    $$
    --- SBBSecho 3.28-Linux
    * Origin: Capitol City Online (618:250/10)
  • From Mike Powell@618:250/10 to All on Fri Jun 12 09:29:44 2026
    FOUS30 KWBC 120808
    QPFERD

    Excessive Rainfall Discussion
    NWS Weather Prediction Center College Park MD
    408 AM EDT Fri Jun 12 2026

    Day 1
    Valid 12Z Fri Jun 12 2026 - 12Z Sat Jun 13 2026

    ...THERE IS A MARGINAL RISK OF EXCESSIVE RAINFALL FROM THE SOUTHERN
    ROCKIES THROUGH THE MID-SOUTH, MID-ATLANTIC, AND NORTHEAST AS WELL
    AS FOR CENTRAL AND SOUTHWEST FLORIDA...

    ...South-Central States through Northeast...

    An upper trough over Michigan early this morning will shift east
    across the Northeast through tonight. Prefrontal activity ahead of
    the associated cold front persists over Lake Erie and the lower
    Ohio Valley with stronger activity over the Oklahoma/Arkansas
    border early this morning. Deep moist convection develops diurnally
    today ahead of the cold front east of the Mid-South and a warm
    front lifting over the southern Plains. An extensive Marginal Risk
    remains from the southern Rockies/Sacramento and Davis Mtns across Texas/Oklahoma, the Mid-South/Tennessee Valley and over New
    England. Some activity is still progged over the Central
    Appalachians, so the Marginal Risk was maintained there, though it
    is a notably low risk compared to northern New England and the
    Tennessee Valley where PW anomalies are over 2 sigma (more like a
    peak of 1.5 sigma in the Mid-Atlantic). Most of this activity will
    be fairly progressive hence no Slight Risks at this time.

    Some trimming of the north side to the Marginal Risk was made,
    though timing tonight with surging Gulf moisture limits that
    reduction, particularly based on the 06Z HRRR with central
    Missouri activity late tonight.

    ...Central and Southwest Florida...
    Anomalous moisture will reside over southwest and central portions
    of the Florida Peninsula today, though it should be a little less
    in terms of PW compared to Thursday. Convection along the sea
    breezes should produce very heavy rainfall that could lead to
    flooding concerns for urban areas in Central and Southwest Florida.
    A Marginal Risk remains in effect with Tampa Bay removed due to CAM
    consensus to the east/south of there.

    Jackson


    Day 2
    Valid 12Z Sat Jun 13 2026 - 12Z Sun Jun 14 2026

    ...THERE IS A SLIGHT RISK OF EXCESSIVE RAINFALL FOR PORTIONS OF THE
    CENTRAL PLAINS THROUGH THE MIDDLE MISSISSIPPI VALLEY INTO THE
    LOWER OHIO VALLEY...

    An upper trough swings down the northern Plains Saturday, pushing a
    cold front across the central Plains and Midwest through Saturday
    night. Meanwhile, a warm front tracks from Oklahoma through
    Illinois ahead of the cold front, creating focus for strong
    convergence in a very warm, moist, and unstable air mass. Resultant
    heavy thunderstorms look to organize and repeat from the central Kansas/Oklahoma border through central/southern Illinois and
    western Kentucky where the Slight Risk was expanded a bit.
    Particular focus for heavy rain remains near the Kansas/Missouri
    border where a higher than normal Slight Risk is noted. Scattered
    instances of flash flooding can be expected and a targeted Moderate
    Risk is possible.

    More isolated heavy thunderstorms are also expected over the
    eastern New Mexico and west Texas terrain and nearby plains where
    the Marginal Risk remains.

    The Marginal Risk was removed from most of Michigan based on the
    00Z high-res solutions available with little PW anomaly noted.

    Jackson


    Day 3
    Valid 12Z Sun Jun 14 2026 - 12Z Mon Jun 15 2026

    ...THERE IS A SLIGHT RISK OF EXCESSIVE RAINFALL FOR PORTIONS OF
    TEXAS AND THE LOWER MISSISSIPPI VALLEY...

    ...Southern Rockies, Texas to Southeast...

    A cold front pushes down the Southern Plains into Texas on Sunday.
    This shunts the heavy rain focus south of Saturday and provides a
    strong focus for convective development in a rich Gulf-sourced
    moisture environment. PW anomalies are 2 to 3 sigma above normal
    across Texas (south of the Panhandle) by that afternoon with 2
    sigma anomalies expanding east to Alabama by late Sunday night.
    Expansion of the Slight Risk to both North Texas and the Houston
    metro areas are warranted given the environment as well as the 00Z
    consensus of the UKMET and EC-AIFS for the Houston area, and the
    RRFS and RDPS for North Texas. Furthermore, a decent signal for
    lasting thunderstorm development is over West Texas in the Permian
    Basin into the Concho Valley, so a Slight Risk was raised there as well.

    Additional terrain driven diurnal activity is expected over the
    Southern Rockies/Sacramento and Davis Mtns. This activity should
    spread southeast through the evening, so the Marginal Risk was
    expanded over the southern High Plains.

    A surge of moisture up the southern Appalachians Sunday morning
    brings enough of a heavy rain threat for a Marginal Risk expansion
    up to the westernmost section of Virgina.

    ...Hampton Roads and Delmarva...
    Southwesterly low level flow from the Carolinas bring 2" PW to the
    Mid- Atlantic coast Sunday afternoon ahead of a cold frontal
    passage that night. Evening thunderstorms should be heavy and slow
    enough to warrant a Marginal Risk.

    Jackson


    Day 4 and Day 5

    Valid 12Z Mon Jun 15 2026 - 12Z Wed Jun 17 2026

    ...A SLIGHT RISK OF EXCESSIVE RAINFALL EXISTS FOR PORTIONS OF THE
    SOUTHERN PLAINS, LOWER MISSISSIPPI VALLEY, AND THE SOUTHEAST...

    Overall, not much change from the previous forecast, with the
    overnight guidance continuing to present a good signal for highly-
    efficient training storms along a slow-moving front settling into the region.

    Models continue to show a cold front settling slowly south though
    the southern Plains, lower Mississippi Valley, and the Southeast as
    shortwave energy gradually amplifies a broad upper trough centered
    along the Mississippi Valley on Monday. A deepening pool of
    moisture along the front, fed by southerly low level inflow from
    the western Gulf, will fuel the potential for highly-efficient
    showers and storms. Guidance continues to show PWs increasing to
    2.25 inches (2.5 to 3 std dev above normal) along and ahead the
    front from south South Texas to southern Alabama on Monday.
    Interacting with this moisture is expected to be an area of
    enhanced ascent provided by right-entrance region upper jet forcing
    positioned along the base of the amplifying trough. In addition to
    the deep moisture and large-scale ascent, repeating storms are
    expected to raise the potential for heavy amounts and flash
    flooding concerns. A Slight Risk was maintained from southeastern
    Texas to central and southern Alabama on Day 4.
    By Tuesday, the upper trough axis begins to shift to the east,
    pushing the front, deeper moisture, and the better chance for heavy
    rain farther south and east along the Gulf Coast. For Day 5, a
    Slight Risk was drawn from southeatern Lousiana to southwestern Georgia.

    While Slight Risks were drawn for both periods, given the potential
    for several inches of rain in some locations, an upgrade to a
    Moderate Risk may be required in future updates if the signal
    persists as the event draws nearer.

    Pereira
    $$
    --- SBBSecho 3.28-Linux
    * Origin: Capitol City Online (618:250/10)
  • From Mike Powell@618:250/10 to All on Sat Jun 13 08:24:41 2026
    FOUS30 KWBC 130736
    QPFERD

    Excessive Rainfall Discussion
    NWS Weather Prediction Center College Park MD
    336 AM EDT Sat Jun 13 2026

    Day 1
    Valid 12Z Sat Jun 13 2026 - 12Z Sun Jun 14 2026

    ...THERE IS A MODERATE RISK OF EXCESSIVE RAINFALL FOR SOUTHWESTERN MISSOURI...

    In coordination with SGF/Springfield, MO and EAX/Pleasant Hill, MO
    forecast offices, the Moderate Risk was shifted south out of the
    Kansas City metro with this update, but expanded southeast to cover
    more of the Missouri Ozarks. CAMs guidance of the QPF footprint for
    the day has followed a very common pattern, which is to shift the
    heaviest rainfall totals southward. Thus, it appears the greatest
    flash flooding threat has shifted out of the Kansas City metro.
    This is most certainly not to say that the flooding threat has
    reduced to zero for the Kansas City metro, which remains in a
    higher-end Slight, but that the greatest impacts from flash
    flooding due to heavy rainfall are no longer expected to reach
    Moderate Risk thresholds in the Kansas City metro. However, not far
    to the south, the threat remains significant.

    Training thunderstorms are expected to begin across Missouri this
    afternoon. The training and overall coverage of the thunderstorms
    will increase during the evening with the usual diurnal
    strengthening of the low-level jet. This will pump abundant
    tropical moisture into Missouri from the southwest on 40+ kt winds
    at 850 mb. Since the line of storms is expected to align northwest
    to southeast, the storms will be orthogonal to that southwesterly
    flow, which will be essential for the continued redevelopment and
    training of additional convection as the cells within the line
    track southeastward. Once the storms reach around the Arkansas
    border, the low level jet weakens significantly. This should allow
    for breaks to develop in the line from Arkansas into Tennessee,
    which will greatly diminish the flash flooding threat in those
    states. The topography of the Ozarks across southern Missouri
    supports a heightened flash flooding threat as the mountains
    quickly funnel the heaviest rains into narrow valleys, worsening
    the impacts of any flooding that develops there. This fact too
    supports the southeastward expansion of the Moderate Risk area.

    Meanwhile, a strong cold front will push southeastward out of the
    Plains and eventually into Missouri. This front will end all of the
    rain from northwest to southeast. This too supports the south and
    eastward shifting of the greatest flash flooding threat. While
    portions of far eastern Kansas still will have a threat for
    extended periods of heavy rain, the advancing front reaching those
    areas before points further east should also reduce the time heavy
    rain will impact eastern Kansas, allowing for the Moderate to be
    trimmed a bit. That said, there remains considerable uncertainty as
    to how far east the best lines of training thunderstorms will set
    up, so far eastern Kansas remains in an elevated threat for flash flooding.

    Guidance has come into better agreement that the heaviest rains
    will occur over Missouri today and tonight, and will struggle to
    continue further north and east. Thus, the inherited Slight Risk
    area over Iowa, most of northern Illinois, and all but the
    southwestern tip of Indiana was downgraded to a Marginal Risk with
    this update.

    ...Florida...

    A Marginal Risk area was introduced with this update for all of the
    Florida Peninsula. Abundant moisture and slow-moving thunderstorms
    are expected to develop all up and down the Peninsula this
    afternoon. Since the storms will be stationary, it stands to reason
    that the most heavily impacted areas will see extended periods of
    heavy rain. HREF neighborhood probabilities for over 3 inches of
    rain are over 70% for the entire Peninsula. Thus, while the urban
    areas on both east and west coasts are more flood-prone and are
    likely to miss out on the heaviest rains, any urban areas such as
    Orlando in the middle of the Peninsula could have isolated
    instances of flash flooding.

    Wegman


    Day 2
    Valid 12Z Sun Jun 14 2026 - 12Z Mon Jun 15 2026

    ...THERE IS A SLIGHT RISK OF EXCESSIVE RAINFALL FOR AREAS FROM
    SOUTHERN NEW MEXICO THROUGH WESTERN MISSISSIPPI...

    A slow-moving but potent cold front will approach portions of north
    Texas through into Arkansas on Sunday. The MCS that caused the
    Moderate Risk flooding in Missouri Saturday night will be
    responsible for the heavy rains that elevate northeast Texas
    through the lower Mississippi Valley into the Slight Risk
    category. Associated heavy rain will be ongoing at the start of the
    period Sunday morning, and will weaken and dissipate by midday.
    Since the forward/southward progression of the heavies rains will
    slow after daybreak Sunday, some areas may see several hours of
    weakening but still heavy rains. Abundant moisture will remain in
    place south of the front, as PWATs rise as high as 2.25 inches.
    Thus, any cells producing rains will have no trouble doing so
    efficiently. During the afternoon and evening, this area may see
    additional widely scattered storms with the strong front stalled
    out in the area, but coverage will be somewhat in question as the
    stalled out front alone will not be enough forcing due to flow on
    either side of the front weakening to light and variable winds.

    Further west into west Texas and New Mexico, a shortwave trough
    running into some of the same Gulf moisture as further east should
    allow for scattered showers and thunderstorms to develop in
    clusters from the afternoon well into the evening. Topographic
    assistance by the Sacramento Mountains and other ranges may locally
    produce heavy rains, where any burn scars may take over at raising
    the flash flooding risk. The same front extends into the
    Appalachians and interior Northeast. While the storms will be
    racing in these areas, the abundance of moisture advecting north
    into the front will support the storms in their capability of
    producing heavy rainfall. The Marginal Risk for these areas was
    expanded along the Canadian border through northern Maine.

    The Marginal for portions of the Mid-Atlantic was split into 2
    areas with this update. One for the I-95 corridor from DC to
    Philly, and a second for the Hampton Roads area. Abundant
    Gulf/Atlantic moisture in these areas will support fast-moving but
    training storms capable of producing heavy downpours. Due to
    ongoing drought, the threat really is focused on the urban areas
    where FFGs are lower. The intermediate rural areas were removed
    with this update as any training storms that occur over most of the
    Delmarva will be over rural and flood-resistant/flat areas.

    Wegman


    Day 3
    Valid 12Z Mon Jun 15 2026 - 12Z Tue Jun 16 2026

    ...THERE IS A SLIGHT RISK OF EXCESSIVE RAINFALL FOR PORTIONS OF THE
    LOWER Mississippi VALLEY TO EASTERN TEXAS...

    A large, half-continent sized upper level low over northern Ontario
    will spin numerous shortwaves around its periphery over the eastern
    2/3 of the country. The jet stream will coincide with a strong but
    stalled out cold front over north Texas and southern Arkansas. To
    the south of that front, Gulf moisture will pool to well-above
    normal levels, with PWATs to 2.25 inches over east Texas and
    northern Louisiana. When the shortwaves track over that cold front,
    it will both allow it to continue drifting southward, but also
    provide sufficient upper level forcing to trigger numerous and
    persistent thunderstorms along the east-west oriented front and
    south. This will support an extended duration of training storms,
    especially from east Texas through southwest Mississippi. A
    higher-end Slight remains in effect for this area. The inherited
    Slight was trimmed out of south-central Texas and central Alabama
    on the west and east ends, but expanded north-south over Louisiana
    through the Houston Metro. Rainfall totals in some areas could
    easily exceed 6 inches, with totals to 10 inches in localized areas
    possible due to the extended duration of heavy rain, especially
    along the Texas/Louisiana border. The area remains in a higher end
    Slight for now primarily due to very high FFGs and dry soils in the
    area, but further increases in rainfall, especially as this period
    moves into the CAMs range, could allow for a Moderate Risk upgrade
    due to the very high rainfall amounts forecast for some areas.

    Wegman


    Day 4 and Day 5

    Valid 12Z Tue Jun 16 2026 - 12Z Thu Jun 18 2026

    ...A SLIGHT RISK OF EXCESSIVE RAINFALL EXISTS FOR PORTIONS OF THE
    CENTRAL GULF COAST...

    The first half of the medium range will see two particular threats
    for flash flooding. First, along the Gulf Coast, a stationary
    front will work in tandem with with tropical moisture to develop
    thunderstorms capable of torrential downpours both on Day 4
    (Tuesday) and Day 5 (Wednesday). There is greater confidence in
    Tuesday's flash flood threat given better model agreement in
    placement of QPF and the nearby frontal boundary remaining strong
    enough to help trigger numerous showers and thunderstorms. PWs
    will remain above 2.0" in many cases as well, allowing developing
    thunderstorms to contain highly efficient rainfall rates. Soils
    will be more saturated in wake of Monday's thunderstorms as well,
    making the region more susceptible to flash flooding. The forecast
    remains largely on track for Tuesday (Day 4) with only some minor
    tweaks to the inherited Marginal and Slight Risks to more closely
    resemble the latest WPC QPF. By Wednesday (Day 5) the frontal
    boundary will undergo frontolysis and the source of lift at the
    surface will weaken. However, ensemble guidance continues to show
    ample tropical moisture along the Central Gulf Coast, which at by
    Wednesday will have dealt with multiple rounds of Excessive
    Rainfall. A Marginal Risk was introduced along the I-10 corridor
    from the Houston metro on east to the FL Panhandle to account for
    the flash flood potential around the more urbanized communities
    along the central Gulf Coast.

    Farther north, Wednesday looks like an active day from the Midwest
    on east into the OH Valley. A 500mb shortwave trough racing east
    towards the Great Lakes late Wednesday will provide healthy upper-
    level ascent aloft to foster the development of low pressure.
    Meanwhile, a strengthening LLJ will direct anomalous moisture
    located over the South northward into the region. NAEFS shows an
    impressive IVT for mid-June that surpasses 750 kg/m/s over the
    eastern Corn Belt that will provide copious amounts of moisture.
    Guidance is not in agreement yet as to which locations are most
    favored to witness the heaviest thunderstorm activity. Fast storm
    motions should also help to limit residency times of developing
    storms. That said, PWs ranging between 1.75-2.0" will be the norm
    late Wednesday with storms likely containing efficient rainfall
    rates. A Marginal Risk was introduced to account for the localized
    flash flood potential on Wednesday from the Middle MS River on east
    into the OH Valley.

    Mullinax
    $$
    --- SBBSecho 3.28-Linux
    * Origin: Capitol City Online (618:250/10)