Subj : MESO: Nws Weather Prediction Center College Park Md To : wx-storm@lists.illinois.edu From : COD Weather Processor Date : Sat May 13 2023 05:02:05 AWUS01 KWNH 130502 FFGMPD TXZ000-131100- Mesoscale Precipitation Discussion 0283 NWS Weather Prediction Center College Park MD 101 AM EDT Sat May 13 2023 Areas affected...Much of Central/Southern TX Concerning...Heavy rainfall...Flash flooding likely Valid 130500Z - 131100Z SUMMARY...Widespread heavy showers and thunderstorms will continue to advance east across large areas of central and southern TX. Scattered areas of flash flooding are likely and especially with focus on the more urbanized corridors. DISCUSSION...The latest radar imagery shows a large-scale MCS with widespread heavy shower and thunderstorm activity continuing to advance east across large areas of central and southern TX. This convective outbreak is all being driven by the advance of a shortwave trough from northern Mexico and across the middle Rio Grange Valley. The energy and leading edge of the MCS is interacting with a very moist and unstable airmass characterized by MLCAPE values of 2500 to 3500 J/kg and PWs of 1.5 to 1.75 inches. Expect the convection over the next several hours to continue to bow off to the east through much of the remainder of central and southern TX and extending all the way down through the lower Rio Grange Valley and nearby areas of the western Gulf Coast going through dawn. Rainfall rates of as much as 1 to 2 inches/hour are expected to continue with the stronger cells and this will be aided by the persistence of a southeast low-level fetch off the western Gulf of Mexico which will maintain favorable moisture and instability transport throughout the night. Some localized repeating/training of some of the convection will be possible and especially over areas of south-central TX and this is where the overall heaviest rainfall potential will be for the remainder of the night. Some localized rainfall amounts of 2 to 4 inches are likely with isolated heavier amounts possible. Scattered areas of flash flooding are generally likely given the anticipated rainfall amounts, with the more urbanized locations expected to be most susceptible to runoff problems. This will include a corridor from San Antonio to Austin and Waco over the next several hours. Areas across the lower Rio Grange Valley from Zapata to McAllen will also need to be closely monitored for locally very heavy rainfall and concerns for flash flooding. Orrison ....Please see https://urldefense.com/v3/__http://www.wpc.ncep.noaa.gov__;!!= DZ3fjg!64FnfK3HsoISRlXKnELyc_SAFTldMHEz900JGdDMNYBeR2wS3ulwBlS4AoJ-pvnxjp5_= e3Lri20YiraK2kxboOcchFw$ for graphic product... ATTN...WFO...BRO...CRP...EWX...FWD...HGX...SJT... ATTN...RFC...WGRFC...NWC... LAT...LON 32609770 32259697 31419656 29779639 28409684=20 27289743 26129719 25889785 26569926 27309962=20 27649995 28040026 28660053 29080083 29400099=20 29830076 30199971 30619903 31179870 31969872=20 32409836=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 3.14-Linux * Origin: capitolcityonline.net * Telnet/SSH:2022/HTTP (1:2320/105) .