Subj : MESO: Nws Weather Prediction Center College Park Md To : wx-storm@lists.illinois.edu From : COD Weather Processor Date : Sat Apr 05 2025 22:46:30 AWUS01 KWNH 052245 FFGMPD MSZ000-LAZ000-TXZ000-060430- Mesoscale Precipitation Discussion 0130 NWS Weather Prediction Center College Park MD 644 PM EDT Sat Apr 05 2025 Areas affected...Southeast Texas and Southwest Louisiana Concerning...Heavy rainfall...Flash flooding possible Valid 052244Z - 060430Z SUMMARY...Inflow convection into the much more robust showers and storms over northern Louisiana has been intensifying over the past few hours. Daily record precipitable water in the column is supporting convection with very efficient warm-rain processes. Localized rainfall rates to 2 inches per hour are expected. Flash flooding is possible, especially in urban areas, small streams and creeks, and other flood-prone, low-lying areas. DISCUSSION...An impressive low level jet is advecting incredibly moist air from the Gulf northward on 40-45 kt southerly winds from 925 through 850 mb. This has pushed PWATs into record territory at Lake Charles. The storms are being driven by a very slow moving upper level low and associated surface cold front that are providing ample lift to support storms that have been producing rainfall rates to 2 inches per hour near and just northeast of Houston. This surface based convection will continue into the evening hours as none of the ingredients supporting very heavy rainfall will be abating. Further, recent heavy rainfall across the bayous of Louisiana have lowered the thresholds needed for flooding caused by these storms as they slowly track east across far southeast Texas and southwest Louisiana. CAMs guidance has struggled by underdoing both the coverage and rainfall intensity of these storms so far. However, there is reasonable agreement that the heaviest rainfall over the next 6 hours (for southeast Texas and southwest Louisiana) will be across the southeasternmost counties in Texas and the southwesternmost parishes of Louisiana. Additional inflow convection may develop further east towards central Louisiana and Baton Rouge later tonight in response to the eastward movement of the convection further north, but there's considerably more uncertainty for the eastern half of the MPD area. Given the storms from Houston north and east have developed into a training pattern with additional storms forming on the front edge of the line near Houston, this pattern of training is likely to continue into the evening hours given the very slow movement of the parent cold front causing these heaviest storms. Flash flooding is possible with these training storms, especially in southeast Texas closest to the heaviest storms. Impacts are most likely in urban areas around and the eastern suburbs of Houston, in already full streams and creeks, and flood-prone low-lying areas. Wegman ....Please see https://urldefense.com/v3/__http://www.wpc.ncep.noaa.gov__;!!= DZ3fjg!7biR7nHxootvLUv5Wj5Z8zVrTIJhXtlWsjMklbNl1sH6mP0x7whwBUtUF1JntcuPPYOh= Gq1DwLoM9ZR7vhc6R8e2SXo$ for graphic product... ATTN...WFO...HGX...JAN...LCH...LIX...SHV... ATTN...RFC...LMRFC...WGRFC...NWC... LAT...LON 31909174 31829127 31619117 30809146 30139184=20 29549215 29579267 29769335 29629425 29169496=20 29459553 29979542 30519524 30859508 31239487=20 31579467 31579464 31449396 31549321 31859239=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) .