Subj : MESO: Nws Weather Prediction Center College Park Md To : wx-storm@lists.illinois.edu From : COD Weather Processor Date : Sat Jul 05 2025 05:40:12 AWUS01 KWNH 050538 FFGMPD TXZ000-050935- Mesoscale Precipitation Discussion 0592 NWS Weather Prediction Center College Park MD 138 AM EDT Sat Jul 05 2025 Areas affected...central TX Concerning...Heavy rainfall...Flash flooding likely Valid 050537Z - 050935Z SUMMARY...Localized heavy rainfall will be likely across portions of central TX over the next 2-4 hours. Flash flooding will result from rainfall rates in excess of 3 in/hr at times, especially if heavy rain cores can edge eastward toward Austin/Round Rock and the I-35 corridor. DISCUSSION...0510Z radar imagery from KGRK showed a slow moving thunderstorm in western Travis County with MRMS-derived hourly rainfall of 4 to 5 inches and at least one gauge report from LCRA of 4.98 inches per 60 minutes ending 0510Z near Largo Vista. This cell appeared to be located just north of a remaining mesoscale circulation just on the cool side of a remnant rain-cooled boundary from Friday's rainfall combined with a trough/wind shift axis that extended southwest to the Rio Grande across Webb County. SPC mesoanalysis and 04Z RAP data valid at 05Z showed a stable airmass across the Hill Country and northern TX while MLCAPE of 500-1000 J/kg resided along and southeast of I-35 from Austin southward. 00Z soundings from DRT, FWD and CRP showed PW values at or above the 90th percentile and tropical moisture was still in place in the vicinity of an elongated low-mid level low which was located over central TX. S to SSE 850 mb winds of 10-20 kt are expected to continue overnight with advection of weak instability back toward the northwest and focused convergence near the remnant mesoscale vortex. Weak deeper mean layer winds of 10 kt or less will favor slow to nearly stationary movement of heavy rainfall with hourly rainfall exceeding 3 inches at times. The duration of the core of heaviest rainfall is uncertain, and it may begin to drift to the northwest as the instability gradient pushes northwest over the next couple of hours. However, present trends indicate near stationary net movement with continued very high rainfall rates continuing in the vicinity of western Travis/Williamson and eastern Burnet counties. Otto ....Please see https://urldefense.com/v3/__http://www.wpc.ncep.noaa.gov__;!!= DZ3fjg!87mFxu6nHHQCCpP1tt7fYLNAnwSHTk2ekXwo0vui6NRuvm_8Sj-CylFvs40E7cMlMgBC= QBpXI4z5yijlSGBZdZW46j0$ for graphic product... ATTN...WFO...EWX...FWD... ATTN...RFC...FWR...NWC... LAT...LON 31769776 31619741 31219713 30789731 30409750=20 30069771 30039796 30249830 30689845 31489825=20 =20=20=20=20=20=20=20=20=20=20=20=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) .