Subj : MESO: Nws Weather Prediction Center College Park Md To : wx-storm@lists.illinois.edu From : COD Weather Processor Date : Fri May 30 2025 09:25:36 AWUS01 KWNH 300925 FFGMPD TXZ000-301300- Mesoscale Precipitation Discussion 0335 NWS Weather Prediction Center College Park MD 524 AM EDT Fri May 30 2025 Areas affected...south-central TX Concerning...Heavy rainfall...Flash flooding possible Valid 300923Z - 301300Z SUMMARY...A localized flash flood threat will continue for portions of south-central TX until about 13Z with peak hourly rainfall of 2 to just over 3 inches possible. DISCUSSION...09Z radar imagery over central to south-central TX showed a southward advancing convective line in the process of overtaking nearly a stationary cell over southeastern Kinney County where MRMS has estimated 3+ inches of rain in an hour. The cell formed on a surface convergence axis marking the leading edge of higher surface moisture and within a relative max in MLCAPE with SPC mesoanalysis data showing 3000 to 3500 J/kg centered over Kinney and Maverick counties. In the upper levels, flow was noted to be diffluent on water vapor imagery, likely contributing to lift over the region. The convective line is likely to continue advancing south over the next 2-4 hours, with embedded pockets of intense, efficient rainfall due to the combination of low level moisture from the Gulf and tropical moisture in the mid-upper levels emanating from Tropical Storm Alvin in the eastern Pacific. While the main low level convergence axis is being overtaken by the convective line...which should remain progressive...subtle areas of wind convergence were noted in surface observations between the Edwards Plateau and the lower/middle TX coast that could initiate new thunderstorms in advance of the convective line due to the unstable environment, which could allow for additional, but localized spots of 2 to 3+ in/hr rainfall given slow cell movement. There is also non-zero potential for west-east short term training falling atop scattered portions of the state that have received 200 to 400 percent of normal rainfall over the past week, which may increase the potential for runoff. Overall, the flash flood threat appears limited in scope, but a localized concern will linger for another few hours over portions of south-central TX. Otto ....Please see https://urldefense.com/v3/__http://www.wpc.ncep.noaa.gov__;!!= DZ3fjg!5C2FzRdXN7Ca3wAGL9-G9ZhYwqcMttFKWCVJrQvabXsZTqVaifSkOD-7CWqUD-Rxh1LO= Uv6-t9sYDeDD_9SDVmrWfXQ$ for graphic product... ATTN...WFO...CRP...EWX... ATTN...RFC...FWR...NWC... LAT...LON 29689729 28889688 28269864 28089972 28260030=20 28830076 29190085 29380062 29499972=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) .