Subj : MESO: Nws Weather Prediction Center College Park Md To : wx-storm@lists.illinois.edu From : COD Weather Processor Date : Tue Sep 03 2024 07:01:00 AWUS01 KWNH 030700 FFGMPD TXZ000-031300- Mesoscale Precipitation Discussion 0967 NWS Weather Prediction Center College Park MD 300 AM EDT Tue Sep 03 2024 Areas affected...South-Central to Central to Northwest Texas... Concerning...Heavy rainfall...Flash flooding likely Valid 030700Z - 031300Z SUMMARY...Widely scattered flash flooding remains possible with shallow, slow moving showers crossing compromised soil conditions. DISCUSSION...GOES-E WV suite depicts a closed low at the base of a WSW to ENE Westerlies trough axis over the northern portion of the West Texas Panhandle with the mean trough extending toward the southern Big Country where a strengthening MCV continues to lift north-northeast into Northwest Texas. Broad transverse banding along the northern semi-circle of the wave depicts solid outflow/divergence aloft to strengthen the wave supporting slantwise ascent across the Hill country thought the 700-500mb layer into the broad right entrance. This north-south axis through the Hill country and Triangle of central Texas is also the leading edge of the northern extension of the easterly wave crossing eastern Texas. Behind the wave, surface to 850mb flow is strengthening with a SW-NE axis of increased theta-E/unstable air that is defined well in the TPW/MUCAPE fields from RAP analysis.=20 As this enhanced moisture/unstable air reaches the Hill country and the mid to upper-level divergent/slantwise ascent pattern; expect additional shallow topped showers to develop into west to east banded like features before slowing and turning northward into the mid-level trof from the exiting shortwave feature.=20=20 While dynamic forcing/cell motions are favorable for convergence/slow motions across northern South-central TX into the Hill country, instability is fairly limited with gradient of MUCAPE of 500-1000 J/kg generally along and south of 32N. As such, convection is likely to remain scattered and shallow in nature. However, given the bulk of the high total moisture content is in the lowest layers (15kft), moisture loading and warm cloud processes will allow for efficient rainfall rates, but unless training occurs, hourly totals are probable to remain below 1-1.5".=20 However, rainfall throughout the area today has resulted in solid infiltration with NASA SPoRT 0-40cm relative soil moisture ratios increasing into the 70-80% range; and FFG values have crashed to below 1.5"/hr with broad areas of sub .5"/hr rates across the northern Hill country into the southern Big Country today. So while the entire area is not likely to experience scattered 1" totals through the next 6 hours, an isolated spot of 3-4" is possible; but it will not take much for above average run-off with these intense sub-hourly/instantaneous rain rates with warm cloud processes. As such, widely scattered to scattered focused areas of flash flooding will be expected through the late overnight/early morning hours. Gallina ....Please see https://urldefense.com/v3/__http://www.wpc.ncep.noaa.gov__;!!= DZ3fjg!7PTksmae3A08yZDZ2KHL_szOV_zDSQmBbS8EDY9KOUa5YC068mugv4twt548W-kak-vQ= r4o2V9Aeqv2dvb2tIWoimQk$ for graphic product... ATTN...WFO...EWX...FWD...LUB...MAF...SJT... ATTN...RFC...WGRFC...NWC... LAT...LON 33379809 33249739 32929687 32569688 31959761=20 31219827 30999837 29659853 29039936 28940075=20 30230147 31510146 32450093 33040034 33329944=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) .