Subj : MESO: Nws Weather Prediction Center College Park Md To : wx-storm@lists.illinois.edu From : COD Weather Processor Date : Sun Sep 01 2024 09:43:30 AWUS01 KWNH 010943 FFGMPD TXZ000-011500- Mesoscale Precipitation Discussion 0959 NWS Weather Prediction Center College Park MD 542 AM EDT Sun Sep 01 2024 Areas affected...Upper Texas Coast... Concerning...Heavy rainfall...Flash flooding possible Valid 010945Z - 011500Z SUMMARY...Training band of efficient warm cloud tropical showers to produce 2-3"/hr rates with potential for focused 3-5" totals resulting in possible rapid inundation flooding through early daybreak in proximity to Galveston Bay. DISCUSSION...Pesky stationary surface to 700mb low remains just offshore south-southwest to southwest of Galveston Bay. Core of low level moisture resides in all quadrants with exception of the southwest with Sfc to 850mb values over 1.1" continuing to near ..75" through to 700mb, resulting in over 2.25-2.5" values through depth but loaded in the lowest layers, well below freezing levels to support efficient warm cloud tropical rainfall processes.=20 Tropical profile with diurnal surface heat release off the ocean has added that surface temp to support 2000 J/kg of skinny CAPE profiles for convection. Low level flow is a tad weaker than yesterday at 5-10kts through depth but solid directional convergence will support low level moisture loading to support 2-3"/hr rates. Local observations support that with 1" totals occurring in sites along Galveston Bay in less than 20-30 minutes. Given depth of unidirectional/confluent flow cell motions remain favorable for the northeast quadrant band to allow for training in proximity to Galveston Bay for a few more hours with favorable upstream inflow nearly equalizing in the near term to support training before converging offshore with time or through any eventual cold pool generation after a few hours. As such, spots of 3-5" are possible through 15z, which may result in rapid inundation flooding, especially if cells near urban areas like Galveston Island or west and north of the Bay itself. Still, with potential for back-building offshore, confidence does not remain high enough for extreme totals to designate a likely categorization potential and will remain possible at this time. Gallina ....Please see https://urldefense.com/v3/__http://www.wpc.ncep.noaa.gov__;!!= DZ3fjg!-ABUfKncMyUNplzLjDngoxcq2RILEsmbBvWCWsM-CwoPsrlHSur1LUYpqgH5TZGm3BQl= 5agNRhPAWLmo0B5R-bLnMTc$ for graphic product... ATTN...WFO...HGX...LCH... ATTN...RFC...WGRFC...NWC... LAT...LON 30169483 29989438 29659404 29569409 29229485=20 29069513 29089535 29359544 29809540 30059521=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) .