Subj : MESO: Nws Weather Prediction Center College Park Md To : wx-storm@lists.illinois.edu From : COD Weather Processor Date : Thu Oct 26 2023 15:59:57 AWUS01 KWNH 261559 FFGMPD TXZ000-262158- Mesoscale Precipitation Discussion 1162 NWS Weather Prediction Center College Park MD 1158 AM EDT Thu Oct 26 2023 Areas affected...South-Central to Northeast TX Concerning...Heavy rainfall...Flash flooding likely Valid 261558Z - 262158Z SUMMARY...Multiple rounds of heavy rainfall will continue to impact areas of south-central to northeast TX going into the afternoon hours. Scattered instances of flash flooding will generally be likely, and especially with respect to the more sensitive urban corridors. DISCUSSION...The latest GOES-E IR satellite imagery continues to show slow-moving rounds of heavy showers and thunderstorms impacting portions of south-central TX and especially along an axis from near San Antonio northeastward through Austin and toward Cameron. The convection is rather well aligned with the leading edge of stronger low-level moisture convergence along an outflow boundary/weak front and the confluent nose of a moderately buoyant airmass. MLCAPE values of as much as 1000 to 1500 J/kg are in place, and with a substantial pool of moisture with PWs running upwards of 2.0 to 2.25 inches. The combination of this and some modest shear along with weak right-entrance region upper jet dynamics should continue to drive multiple clusters of heavy showers and thunderstorms heading into the afternoon hours. Some of the activity will likely expand up into areas of northeast TX with time as some weak shortwave energy over central TX advances toward the Red River Valley of the South. Rainfall rates will continue to easily reach into the 1 to 2 inch per hour range and especially over areas of south-central TX where a combination of greater instability and a very deep tropical column will favor high rainfall efficiency for enhanced rates. The 12Z HREF guidance shows the potential for as much as an additional 2 to 4 inches of rain with isolated heavier amounts potentially near 5 inches going through the late afternoon hours. Areas along and east of a line from San Antonio through Austin and Cameron will likely see the heaviest amounts given proximity of greater instability and stronger concerns of training convective cells given the near parallel alignment of the convection with the deeper layer mean flow. Slow cell-motions and high rainfall rates will only add to these concerns. Given the high rainfall rates and additional storm total amounts heading through the afternoon, and with the more sensitive urban corridor considerations, scattered areas of flash flooding will continue to generally be likely. Orrison ....Please see https://urldefense.com/v3/__http://www.wpc.ncep.noaa.gov__;!!= DZ3fjg!5VP-ZAbfatDddtN9Meh8pNjuQJYz2t5g_10qwi8dRwEDILKQzzGOdrTBW3L0X7iTXll-= 145XPRj3kxE2XCbi5XnsgyM$ for graphic product... ATTN...WFO...CRP...EWX...FWD...HGX...SHV... ATTN...RFC...LMRFC...WGRFC...NWC... LAT...LON 32929523 32449460 31769486 30189602 28819736=20 28289825 28229895 28679912 29669859 31189756=20 32449636=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) .