Subj : MESO: Nws Weather Prediction Center College Park Md To : wx-storm@lists.illinois.edu From : COD Weather Processor Date : Wed Nov 26 2025 09:07:30 AWUS01 KWNH 260907 FFGMPD TXZ000-261400- Mesoscale Precipitation Discussion 1252 NWS Weather Prediction Center College Park MD 406 AM EST Wed Nov 26 2025 Areas affected...South TX Concerning...Heavy rainfall...Flash flooding possible Valid 260905Z - 261400Z Summary...A fairly localized flash flood threat will continue over portions of southern TX through sunrise. Slow moving thunderstorms will be capable of hourly rainfall in excess of 2 to 3 inches in an hour with potential for additional totals of 3 to 5+ inches. Discussion...Area radar imagery over southern TX at 0840Z showed a slow moving thunderstorm in the vicinity of Hebronville along with the recent (since 07Z) expansion of a broken line of thunderstorms extending west from Rockport. The line of storms to north of Hebronville appears to be elevated just above the surface given increasing northerly winds at the surface and lowering dewpoints just north of these storms, associated with a cold front which extended through the western Gulf into the lower Rio Grande Valley. While ground truth of observed rainfall at the surface has been limited, the ASOS from KHBV showed 0.88 inches of rain in 8 minutes ending 0735Z. This is an example of what the environment over south TX can produce, represented by MLCAPE of 1000-2000 J/kg and precipitable water values near 1.5 inches (per 08Z SPC mesoanalysis data). The slow moving cold front will begin to move toward the south at a more rapid pace by 12Z and beyond, due to a strong ridge of high pressure to the north building in and a secondary cold front currently moving steadily through central TX. Until then however, the potential for slow moving thunderstorms will continue given a mixture of cell types and cell motions, some of which could be less than 10 kt toward the east. There is also some potential for cells to develop/stall near the coast as a corridor of relatively stronger low level flow near the front (15-20 kt 925-850 mb layer) acts to focus cells along a coastal convergence axis forced by the warmer Gulf waters relative to inland locations. While the potential for flash flooding looks to be isolated, the potential for high rain rates and localized totals in excess of 3-5 inches will maintain concerns for rapid inundation of water until ~14Z, at which point, the cold front is forecast to be moving through Brownsville. Otto ....Please see https://urldefense.com/v3/__http://www.wpc.ncep.noaa.gov__;!!= DZ3fjg!9MR70JC_4x4-U6ClozgFChiBGGoHQgRXY5C8hXC0VU8raHtYF-yjLC3JdDUp3Flb2bBw= quZZ_nlZZT1G0h3xDIRz-kE$ for graphic product... ATTN...WFO...BRO...CRP... ATTN...RFC...FWR...NWC... LAT...LON 28419728 28369661 27979657 27069704 25679698=20 25829839 26089916 26689958 27129972 27759937=20 28169865=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 3.28-Linux * Origin: capitolcityonline.net * Telnet/SSH:2022/HTTP (1:2320/105) .