• DAY2 2/5 Risk Areas Poste

    From Mike Powell@618:250/10 to All on Sat Jun 6 10:03:30 2026
    ACUS02 KWNS 060532
    SWODY2
    SPC AC 060530

    Day 2 Convective Outlook
    NWS Storm Prediction Center Norman OK
    1230 AM CDT Sat Jun 06 2026

    Valid 071200Z - 081200Z

    ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ...

    ...SUMMARY...
    Scattered severe storms capable of large to very large hail, severe
    wind gusts, and perhaps a tornado or two are possible across the
    northern Plains. More isolated severe storms capable locally
    damaging wind gusts may occur across portions of the Mid-Atlantic. A
    brief tornado or two appears possible in eastern Oklahoma and
    western Arkansas.

    ...Synopsis...

    A vorticity maximum and associated mid/upper-level jet streaks
    within the base of broader-scale troughing from the lee of the
    Canadian Rockies into northern Intermountain Region Sunday morning
    are forecast to accelerate northeast through the northern High
    Plains, ahead of an upstream jet segment moving onto the Pacific
    Northwest coast. Elsewhere, an amplified short-wave trough will
    progress through the Northeast, while a more loosely organized
    trough progresses through the central and southern Plains through
    the Ozarks and mid MS Valley.

    At the surface, an area of low pressure and associated pre-frontal
    trough over the western Dakotas will be overtaken by a cold front
    moving out of the northern Rockies. That frontal system will
    continue east into the ND-MN Red River Valley, and southeast into
    the central High Plains by Monday morning. Elsewhere, more of a
    backdoor cold front will progress south/southwest through the
    Northeast into Mid-Atlantic.

    ...Montana and Wyoming into the Dakotas...

    A hot, deeply mixed boundary layer is expected to develop ahead of
    the pre-frontal trough over the western Dakotas Sunday afternoon,
    with the presence of steep low/mid-level lapse rates contributing to
    an axis of moderate to strong instability. Moderate instability is
    expected to extend into eastern MT and northeast WY, owing to
    low-level moisture wrapping around the surface trough. Initial storm development is expected by mid afternoon along the western fringe of
    the instability axis across southeast MT into north-central and
    northeast WY as lift is enhanced by terrain, the cold front, and
    forcing tied to the vorticity maximum and attending jet streaks. A
    separate thunderstorm regime is expected to evolve by late afternoon
    into evening over the western Dakotas as the cold front merges with
    the pre-frontal trough.

    The MT/WY storms are expected to mature in a strongly sheared
    environment, which will favor supercells capable of large hail.
    Initially marginal vertical shear with the western Dakotas storm
    regime is expected strengthen through the evening, supporting the
    potential for supercells capable of large to very large hail and
    severe wind gusts as the primary hazards. Some tornado threat may
    materialize by mid/late evening across portions of north-central ND
    where strengthening low-level shear will coincide with a more moist,
    lower-LCL boundary layer. The magnitude of the threat will be
    contingent on storm mode at that time, given the tendency for more
    linear forcing along the cold front.

    ... Central Virginia into the Chesapeake Bay Area...

    Daytime heating coupled with dewpoints in the 60s will contribute to
    a moderately unstable air mass by afternoon, ahead of a pre-frontal
    wind shift moving into the area from the north. Convergence along
    that boundary along with the glancing influence of the mid-level
    trough passing to the immediate north are expected to support
    isolated to widely scattered thunderstorms during the afternoon
    across the discussion area. Relatively warm mid-level temperatures
    are expected to limit the potential for large hail; however, the
    presence of steep, low-level lapse rates and 30-35 kt of
    northwesterly deep-layer shear appear supportive of locally damaging
    wind gusts through the afternoon into early evening.

    ...Eastern Oklahoma and Western Arkansas...

    Forcing for ascent attendant to a vorticity maximum moving through
    the base of broader-scale troughing is expected to contribute to an
    increase in thunderstorm coverage early in the day. That scenario
    would tend to limit air mass destabilization through the afternoon,
    leaving severe-storm potential in question. However, there is a
    signal in some guidance that a low-level jet will strengthen during
    the afternoon into evening, leading to an increase in low-level
    shear. A concurrent risk for a brief tornado or two may materialize,
    especially with any storms on the southern or western fringe of the
    larger convective footprint. That notion is generally supported by
    the 00z HREF mean 0-1 km SRH, which shows values increasing to
    100-150 m2/s2 by Sunday evening.

    ..Mead.. 06/06/2026

    $$
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    * Origin: Capitol City Online (618:250/10)