• Flood Threat SE TX

    From Mike Powell@618:250/10 to All on Fri Jun 5 09:50:36 2026
    AWUS01 KWNH 051225
    FFGMPD
    TXZ000-051700-

    Mesoscale Precipitation Discussion 0323
    NWS Weather Prediction Center College Park MD
    824 AM EDT Fri Jun 05 2026

    Areas affected...southeastern TX

    Concerning...Heavy rainfall...Flash flooding possible

    Valid 051223Z - 051700Z

    SUMMARY...Widely scattered narrow axes of training showers and
    thunderstorms across southeastern TX may result in isolated
    pockets of flash flooding over the next 4-5 hours. Hourly rainfall
    locally in excess of 2 inches will be possible.

    DISCUSSION...12Z regional radar imagery over the TX Coastal Plain
    depicted scattered showers with embedded thunderstorms, moving
    from SSE to NNW. Low level flow of about 10 to 20 kt (slightly
    stronger over the upper TX coast into the Piney Woods region) was
    oriented perpendicular to the coast, resulting in the widely
    scattered shower activity. Surface observations at 12Z showed the
    reflection of a remnant surface frontal boundary, represented by
    lower dewpoints to its north and east, extending from the northern
    Gulf Coast into southeastern TX. MLCAPE was also reflective of
    this boundary with a gradient shown on the 12Z SPC mesoanalysis
    with 500 to 1500 J/kg located on the warm side of the remnant
    frontal boundary across the TX Coastal Plain, with little to no
    instability to its north. Near this gradient was weakly convergent
    flow in the 0-2 km AGL layer, partially aligned with the mean
    steering flow from the SSE.

    Due to the similar orientation of the low level and steering flow,
    with low level flow slightly stronger than 10-15 kt steering flow,
    some training and brief backbuilding of cells will be possible
    over the next few hours. Southeastern TX was also beneath the
    ridge axis of a broader upper ridge over the Gulf, aiding in weak
    upper diffluence. With GPS PWs of 2.0 to 2.1 inches over
    southeastern TX, the environment will be supportive of efficient
    rainfall with potential for 1 to 2 inches of rain in an hour
    (locally higher possible), and 2 to 4+ inch storm totals.

    While the coverage of these higher rates remains quite uncertain
    and could end up highly localized, portions of southeastern TX
    have picked up 3 to 6+ inches of rain over the past 2-3 days,
    resulting in pockets of higher soil moisture and reduced
    infiltration capacity. Therefore, in addition to urban overlap,
    additional heavy rain of 2 to 4+ inches falling atop any
    hyrdologically sensitive locations could result in isolated flash
    flooding over the next 4-5 hours.

    Otto

    ATTN...WFO...CRP...EWX...FWD...HGX...LCH...

    ATTN...RFC...FWR...NWC...

    LAT...LON 31459581 31229519 30809482 30519443 30209395
    29539397 28609538 27929674 29139734 30869710
    31369652

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