Subj : MESO: Nws Weather Prediction Center College Park Md To : wx-storm@lists.illinois.edu From : COD Weather Processor Date : Mon Apr 21 2025 09:52:53 AWUS01 KWNH 210952 FFGMPD LAZ000-TXZ000-211400- Mesoscale Precipitation Discussion 0153 NWS Weather Prediction Center College Park MD 552 AM EDT Mon Apr 21 2025 Areas affected...southeast Texas, far southwest Louisiana Concerning...Heavy rainfall...Flash flooding possible Valid 210950Z - 211400Z Summary...Local/spotty flash flood potential should continue for at least another 2-3 hours. Discussion...Convection continues to fire along an 850mb confluence axis extending from north-central Louisiana through southeast Texas. Along and ahead of this confluence axis, 1000 J/kg MLCAPE and 1.7 inch PW values were combining with favorable kinematics for slow-moving storms with locally extreme rain rates. In fact, MRMS estimates approximately 6.5 inches of rain in southern Tyler County over the past 3 hours. Nearby convection has also produced 1-2 inch/hr rain rates at times. Recent radar mosaic imagery also depicts an uptick in weaker convection from Tyler County westward and southwestward through Colorado County, suggestive of a continued flash flood threat in these areas over at least the next 2-3 hours. Convective coverage becomes a bit less certain after 13Z or so.=20 Although confluence will remain in place across the discussion area through that time, RAP/SPC Mesoanalyses depict weakening/slackening 850mb flow east of the confluence zone that could cause existing updrafts to struggle against conditional instability aloft. The timing of this scenario is a bit uncertain, however, and recent CAMs maintain convection across the discussion area (perhaps propagating and/or developing toward coastal areas) through at least 15-16Z or so. This area will be re-evaluated for any continuing flash flood potential (and another MPD) after ~13-14Z or so. Cook ....Please see https://urldefense.com/v3/__http://www.wpc.ncep.noaa.gov__;!!= DZ3fjg!8RJo606zd1WMJtEDznN4AR8V65bPUpR3N7_K2A6-J_IjRzYSPsetddO13LsdWa3tKqDf= uRoXyBEla7OZeNXFq18V7EQ$ for graphic product... ATTN...WFO...HGX...LCH...SHV... ATTN...RFC...LMRFC...WGRFC...NWC... LAT...LON 31669341 31289269 30569280 29899379 29159515=20 28739615 29059666 29829618 30479560 31419444=20 =20=20=20=20=20=20=20=20=20=20=20=20 =3D =3D =3D To unsubscribe from WX-STORM and you already have a login, go to https://lists.illinois.edu and use the "Unsubscribe" link. Otherwise email Chris Novy at cnovy@cox.net and ask to be removed from WX-STORM. --- SBBSecho 3.20-Linux * Origin: capitolcityonline.net * Telnet/SSH:2022/HTTP (1:2320/105) .