• MESO: Heavy Rain/Flood TX

    From Mike Powell@618:250/1 to All on Fri May 3 08:14:00 2024
    AWUS01 KWNH 030902
    FFGMPD
    LAZ000-TXZ000-031501-

    Mesoscale Precipitation Discussion 0213
    NWS Weather Prediction Center College Park MD
    502 AM EDT Fri May 03 2024

    Areas affected...southeast Texas

    Concerning...Heavy rainfall...Flash flooding likely

    Valid 030901Z - 031501Z

    Summary...Deepening convection is forming in areas that received
    abundant rainfall yesterday. Sensitive ground conditions will
    likely promote additional runoff and flash flood concerns through
    15Z today.

    Discussion...Renewed development of convection was ongoing in
    earnest this morning generally from Bryan/College Station
    east-southeastward through Gulf waters just south of Cameron, LA
    over the past hour or so. These storms were developing along
    remnant outflow from prior convection yesterday morning, with
    subtle 850mb confluence aiding updrafts amid 1500-2000 J/kg MLCAPE
    and abundant moisture (1.8 inch PW). Unfortunately,
    east-northeasterly storm motions were fostering movement of
    convection into areas of southeast Texas that received abundant
    (2-7 inch) rainfall totals from yesterday, with ongoing
    flood/flash flood impacts continuing. The renewed convective
    development is likely to worsen ongoing flooding and cause new
    flash flooding in at least a few areas across southeast Texas
    through the morning.

    Models/observations suggest that convection will persist across
    the discussion area through at least 15Z, with areas of 1-1.5
    inch/hr rain rates materializing as convection deepens and
    matures. Localized areas of cell mergers could prolong rain rates
    in a few spots as well. FFGs are quite low (0.25-1 inch/hr
    thresholds), further highlighting the sensitivity of the ground
    conditions across the discussion area. Flash flooding is likely
    in this regime.

    Cook

    ATTN...WFO...EWX...FWD...HGX...LCH...SHV...

    ATTN...RFC...LMRFC...WGRFC...NWC...

    LAT...LON 31239501 31069405 30499324 30019309 29689339
    29499411 29629501 29799611 30079670 30489671
    30859634 31209564

    = = =
    --- SBBSecho 3.20-Linux
    * Origin: capitolcityonline.net * Telnet/SSH:2022/HTTP (618:250/1)
  • From Mike Powell@618:250/1 to All on Sun May 5 08:35:00 2024
    AWUS01 KWNH 051329
    FFGMPD
    TXZ000-051800-

    Mesoscale Precipitation Discussion 0228
    NWS Weather Prediction Center College Park MD
    929 AM EDT Sun May 05 2024

    Areas affected...Portions of Southeast Texas

    Concerning...Heavy rainfall...Flash flooding likely

    Valid 051328Z - 051800Z

    SUMMARY...Flash flooding likely as storms developing along a
    boundary west of Houston track along the boundary over
    hydrologically sensitive areas west of Houston and into the
    Houston Metro. Considerable urban flash flooding potential is
    increasing.

    DISCUSSION...Training convection developing west of Houston is
    moving east towards Houston this morning. The storms have formed
    along an outflow boundary that was set by the MCS that is
    departing off to the east. CAMs guidance suggests the boundary
    will remain nearly stationary through the day. Abundant Gulf
    moisture moving in from the Gulf will continue to feed moisture
    and instability into the storms through midday. Thus, the
    potential for significant, considerable, and high-impact urban
    flash flooding is increasing.

    CAMs guidance remains in poor agreement on how this boundary will
    behave through the day today. Much of the guidance is much further
    south with the boundary than where it has actually developed.
    However, they are in better agreement that the boundary convection
    will not only continue to develop, but gradually backbuild west to
    as far as the Rio Grande. Should that occur a follow-up MPD may be
    needed. For now, the area of concern remains for portions of
    Southeast Texas, as regardless of how far west the convection
    develops later, storms are likely to continue in the highlighted
    area.

    Wegman

    ATTN...WFO...EWX...HGX...

    ATTN...RFC...WGRFC...NWC...

    LAT...LON 30299528 30279493 29879455 29419472 29279486
    29179521 28919548 28869636 29179688 29339743
    29749751 30129726 30159733 30259708 30249631
    30259575

    = = =
    --- SBBSecho 3.20-Linux
    * Origin: capitolcityonline.net * Telnet/SSH:2022/HTTP (618:250/1)