Subj : MESO: Nws Weather Prediction Center College Park Md To : wx-storm@lists.illinois.edu From : COD Weather Processor Date : Tue Jul 23 2024 17:02:14 AWUS01 KWNH 231702 FFGMPD LAZ000-TXZ000-232300- Mesoscale Precipitation Discussion 0707 NWS Weather Prediction Center College Park MD 100 PM EDT Tue Jul 23 2024 Areas affected...South-Central to Southeast TX...Western LA Concerning...Heavy rainfall...Flash flooding likely Valid 231700Z - 232300Z SUMMARY...Scattered instances of flash flooding will be likely from pockets of heavy showers and thunderstorms going through the afternoon and early evening hours. DISCUSSION...The latest GOES-E satellite imagery in conjunction with dual-pol radar shows a pockets of relatively slow-moving and heavy showers and thunderstorms across south-central TX (including the TX Hill Country) and stretching well off to the east-northeast in a somewhat disorganized fashion across the southeast TX coastal plain and western LA. Multiple outflow boundaries/cold pools are already evolving across the region which is locally helping to focus renewed convective development. Facilitating the convective threat over the next several hours will be the strong diurnal heating cycle with a build-up of a moderately buoyant airmass characterized by MLCAPE values increasing to 1500 to 2000 J/kg. A very moist boundary layer will be a key contributor to this, and the overall depth of moisture with PWs reaching 2.0 to 2.25 inches will support convective cells capable of producing enhanced rainfall rates that may reach 2 to 3 inches/hour. Proximity of a stationary front and the aforementioned outflow boundaries will support the idea of there still be locally focused areas of convection with slow cell-motions. Additionally, there continues to be influence over the region from a mid-level trough digging southeast into the southern Plains region which is yielding some deeper layer ascent to further promote convective activity redeveloping and locally expanding in coverage. The 12Z HREF guidance supports localized clusters of rainfall totals reaching 2 to 4 inches going through early this evening. Given the high moisture environment and overall depth of the warm cloud layer, some isolated 5+ inch amounts cannot be ruled out and especially with the slow cell-motions and potential for cell-mergers. Portions of south-central TX involving the Hill Country remain quite sensitive due to recent and/or ongoing areas of heavy rain, and will tend to be most susceptible to additional flash flooding concerns in the near-term. However, areas farther east into the southeast TX coastal plain that are drier by comparison will also eventually see convection with sufficiently high rates that scattered instances of flash flooding (especially within the urban corridors) will become a concern. ....Please see https://urldefense.com/v3/__http://www.wpc.ncep.noaa.gov__;!!= DZ3fjg!-Foh_G3LDCIRvZZ4MXG0888kuhWJNxXkkrgoljsRsP84W_0-_82wBwUMHokNaAXhJtuJ= JWr3SPmTQYzOUONHUhCNzJc$ for graphic product... ATTN...WFO...CRP...EWX...FWD...HGX...LCH...SHV...SJT... ATTN...RFC...LMRFC...WGRFC...NWC... LAT...LON 32689543 32149373 31329308 30539308 29599390=20 28869554 28219664 27469723 27419794 28399866=20 29079979 29230078 29780105 30300043 30799936=20 31609806 32279721 32649644=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) .