Subj : MESO: Nws Weather Prediction Center College Park Md To : wx-storm@lists.illinois.edu From : COD Weather Processor Date : Thu Oct 26 2023 22:00:03 AWUS01 KWNH 262159 FFGMPD TXZ000-270157- Mesoscale Precipitation Discussion 1163 NWS Weather Prediction Center College Park MD 558 PM EDT Thu Oct 26 2023 Areas affected...Portions of South-Central and Eastern TX Concerning...Heavy rainfall...Flash flooding possible Valid 262157Z - 270157Z SUMMARY...Heavy showers and thunderstorms will continue into the evening hours across portions of south-central and eastern TX. Some additional potential for localized flash flooding will exist, and especially for the more sensitive urban locations. DISCUSSION...The latest radar and satellite imagery shows a broken axis of heavy showers and thunderstorms continuing to impact areas of south-central and eastern TX as a deeper layer axis of tropical moisture and embedded vort energy advances gradually east-northeast across the region. Diurnal heating has contributed to a general expansion of the convective activity over the last few hours given the corresponding increase in boundary layer instability. MLCAPE values especially across south-central TX have increased to as high as 2000 J/kg locally, and the moisture environment is quite impressive with PWs of near 2.25 inches. These PWs are on the order of 2 to 3 standard deviations above normal and are helping to contribute to highly efficient rainfall processes for locally extreme rainfall rates. Over the last few hours, some of the rainfall rates have been as high as 2.5 inches per hour with the stronger convective cores. Over the next few hours, given the thermodynamic environment and persistent channel of at least weak shortwave energy seen in GOES-E WV satellite imagery, the ongoing axis of heavy shower and thunderstorm activity should tend to persist. Some modest right-entrance region upper jet dynamics will be in place as well. By mid-evening, the overall intensity and coverage of convection should begin to wane as a combination of convective overturning and loss of daytime heating fosters greater boundary layer stabilization. The latest HRRR guidance still supports locally an additional 3 to 5 inches of rain where some of stronger cells tend to train over the same area. The 18Z HREF guidance however suggests somewhat lesser totals overall. Regardless, the additional rainfall amounts may result in some additional localized flash flooding concerns, and especially for the more urbanized locations. Orrison ....Please see https://urldefense.com/v3/__http://www.wpc.ncep.noaa.gov__;!!= DZ3fjg!-ziVthUg1MKbn-8zil97KF9Qu4AfM2m_f9M_fbCYluuGGCN9hy-BhSOzOVdnmAqT9L7F= 2zaYcKPOrQqecQ_wxFZt8v8$ for graphic product... ATTN...WFO...CRP...EWX...FWD...HGX...LCH...SHV... ATTN...RFC...WGRFC...NWC... LAT...LON 32019479 31849395 30819460 29249636 28529780=20 28859819 29839739 30649650=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) .