Subj : MESO: Nws Weather Prediction Center College Park Md To : wx-storm@lists.illinois.edu From : COD Weather Processor Date : Thu Nov 20 2025 05:42:19 AWUS01 KWNH 200542 FFGMPD TXZ000-201010- Mesoscale Precipitation Discussion 1233 NWS Weather Prediction Center College Park MD 1241 AM EST Thu Nov 20 2025 Areas affected...portions of central TX Concerning...Heavy rainfall...Flash flooding possible Valid 200540Z - 201010Z Summary...Isolated to widely scattered instances of flash flooding will be possible over portions of central TX including the Hill Country through 10Z. Localized totals of 2 to 4+ inches may occur over a relatively short period of time. Discussion...Regional radar imagery through 0530Z showed widely scattered coverage of thunderstorms over central TX with an increasingly concerning cluster near/south of JCT with only small net-movement over the past hour. The environment over central TX contained anomalous precipitable water values of 1.3 to 1.7 inches and 500-1500 J/kg MLCAPE (SPC mesoanalysis and area soundings from 00Z) with moisture contributions from the tropical eastern Pacific in the mid/upper levels and Gulf of America in the lower levels. 0-6 km mean layer winds were a progressive 20-30 kt toward the northeast but sufficient speed shear was present for organized cells and slower storm motions right of the mean wind. While larger scale forcing ahead of a strong mid to upper level trough/closed low over the CA/AZ border was still well west of TX, the low level response out ahead of this feature was SSE 925-850 mb winds of 20-30 kt with increasing low level moisture values into central TX since Wednesday evening as seen on OSPO LPW imagery in the surface-850 mb layer. Transient axes of low level convergence and upslope flow into the Edwards Plateau are expected to continue to support small clusters of thunderstorms with mean movement off toward the northeast. However, there will likely be areas of upstream convective redevelopment which will allow for training and repeating cells at times. Peak hourly rainfall of 1 to 2 inches (locally higher) is expected within SW to NE axes of training with 3-hr totals of 2-4 inches, although idealized training over a particular location has the potential for rainfall totals over 4 inches in 3 hours. Current thinking is that the coverage of flash flooding through 10Z will remain low enough to keep the "flash flooding possible" wording on this message given dry antecedent conditions, but concerns for rapid rises of water will exist across portions of the sensitive Hill Country despite the dry antecedent grounds. Otto ....Please see https://urldefense.com/v3/__http://www.wpc.ncep.noaa.gov__;!!= DZ3fjg!_LYpBNhMlhdGrOmNgOUQY3aTCioz2NPMkd1VVanuIvyaHF12_R4dS_2zri_aZ5-ZJWhe= ULn-yQhCMPB3_j4eFKk9eD4$ for graphic product... ATTN...WFO...EWX...FWD...SJT... ATTN...RFC...FWR...NWC... LAT...LON 32119869 31429791 30329826 29749881 29269946=20 28930081 29550147 30710103 31759995=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) .