Subj : MESO: Nws Weather Prediction Center College Park Md To : wx-storm@lists.illinois.edu From : COD Weather Processor Date : Mon Jul 22 2024 23:47:30 AWUS01 KWNH 222347 FFGMPD TXZ000-230530- Mesoscale Precipitation Discussion 0700 NWS Weather Prediction Center College Park MD 747 PM EDT Mon Jul 22 2024 Areas affected...Southern Texas... Concerning...Heavy rainfall...Flash flooding possible Valid 222345Z - 230530Z SUMMARY...Scattered flash flooding remains possible across portions of southern Texas where remaining unstable air and sufficient convergence can support cells capable of 2-2.5"/hr and spots of 2-4" into the early overnight period. DISCUSSION...GOES-E waning visible imagery shows a few convective cells/clusters developing at the intersection of outflow boundaries at the edge of the debris/cirrus canopies from prior convective clusters generally in the vicinity of the I-10 corridor. Strong moisture convergence from outflow from the north intersected unstable air near the northern Houston Metro, with tail end of the outflow influence resulting in more scattered cells out toward Travis county. Very deep moisture with over 75F Tds and 2000-2500 J/kg of MLCAPE and the convergence of 10-15kts through the boundary layer has been sufficient for deep warm cloud process within the 2-2.25" TPW moist air mass. This is supporting 2-2.5"/hr rates and with slow cell motions toward the east at 5-10kts, an hour or two result in localized 2-4" totals. Further west of GYB, the sea-breeze is stronger at 20-25kts and is undercutting the unstable air mass resulting in similar strong overturning with cooling tops below -65C fairly rapidly; this band is arched back toward the SW toward UVA and FTN. Similar undisturbed unstable air at the fringe of earlier convective canopy is likely to unzip as the convergence/intersection from weak northerly winds under the cirrus. Similar unstable 2000-2500 J/kg air exists here as well, but steering is a bit more toward the southeast and may be closer to stationary allowing for more localized but more intense areas reaching 3-4" in 1-2hrs before exhausting the remaining unstable air. Similarly scattered incidents of flash flooding will be possible into the early overnight period along the axis. Gallina ....Please see https://urldefense.com/v3/__http://www.wpc.ncep.noaa.gov__;!!= DZ3fjg!41JyAYFNixZgdD2qWl_jgn3Rw-HDiyhdD8kWhwAhC0ck805m_YFyWPWZCSIgXqx25Dyi= MxNQ0QYlXJekacEdWgi3G64$ for graphic product... ATTN...WFO...CRP...EWX...FWD...HGX...LCH... ATTN...RFC...WGRFC...NWC... LAT...LON 30919691 30859584 30849455 30579388 29879406=20 29609519 29359743 28889844 28169929 27739974=20 28330048 29400086 30569870=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) .