Subj : MESO: Nws Weather Prediction Center College Park Md To : wx-storm@lists.illinois.edu From : COD Weather Processor Date : Fri Apr 07 2023 16:32:44 AWUS01 KWNH 071632 FFGMPD TXZ000-072230- Mesoscale Precipitation Discussion 0170 NWS Weather Prediction Center College Park MD 1232 PM EDT Fri Apr 07 2023 Areas affected...central to south-central TX Concerning...Heavy rainfall...Flash flooding possible Valid 071631Z - 072230Z Summary...Localized areas of flash flooding will be possible across portions of central to south-central TX over the next several hours from occasional rainfall rates of 1-2 in/hr on top of nearly saturated soils. Discussion...Scattered showers and thunderstorms were ongoing across south-central/southern TX at 16Z with movement off toward the northeast. This region of TX was located out ahead of an upper trough crossing northern Mexico and focused along easterly and northeasterly convergence centered near 925 mb as noted on VAD wind plots. Instability was elevated and weak, likely less than 500 J/kg but precipitable water values of 1.3 to 1.6 inches (per 15Z SPC mesoanalysis data) were sufficient for heavy rain. A 100-110 kt sampled between 250-200 mb via the 12Z sounding from La Paz, was advancing eastward across northern Mexico. After the ongoing axis of locally heavy rain over south-central TX translates east, additional rounds of showers and thunderstorms will be possible into the afternoon as continued overrunning of the surface front occurs and favorable upper level support continues. Short term forecasts by recent runs of the RAP showed that upper level divergence will increase over south-central TX this afternoon as the upper jet max continues to the east, which may help to increase updraft strength across what should otherwise be an environment characterized by weak instability given only modest mid-level lapse rates for much of the area of concern. Cores of heavy rain should follow the 850-300 mb layer mean wind with brief training of heavy rainfall, supporting 1-2 in/hr rainfall rates and possible flash flooding. This potential will be increased if model forecasts of MUCAPE are too low, but current thinking is that coverage of heavy rain will be localized. Given portions of southern to southeastern TX have received heavy rain over the past 24-48 hours, which has significantly increased soil moisture in some locations, excess runoff will be more likely in a few locations. Otto ....Please see https://urldefense.com/v3/__http://www.wpc.ncep.noaa.gov__;!!= DZ3fjg!8rm3kY2ucyuDNHDoZZsE6r6FIUV8386hwXP60yS1UuSxUgKFs_XDe-0tKSh5DkHRnt-V= aboFu9hLC3zFCQtns1RhzaE$ for graphic product... ATTN...WFO...CRP...EWX...FWD...HGX... ATTN...RFC...WGRFC...NWC... LAT...LON 30649615 30469563 29999550 29639567 28829724=20 28129787 27539850 27439901 27869919 28709920=20 29589886 30109845 30559770=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) .