Subj : MESO: Nws Weather Prediction Center College Park Md To : wx-storm@lists.illinois.edu From : COD Weather Processor Date : Sun May 07 2023 00:17:05 AWUS01 KWNH 070017 FFGMPD TXZ000-OKZ000-070500- Mesoscale Precipitation Discussion 0229 NWS Weather Prediction Center College Park MD 815 PM EDT Sat May 06 2023 Areas affected...Portions of Northern/Central TX Concerning...Heavy rainfall...Flash flooding possible Valid 070015Z - 070500Z SUMMARY...Gradually merging clusters of heavy showers and thunderstorms this evening may result in some isolated instances of flash flooding. DISCUSSION...Late-day satellite imagery in conjunction with radar shows several clusters of supercell convection impacting areas of central and northern TX near and to the east of a very well-defined dryline. This is being strongly aided by a low-amplitude shortwave trough ejecting northeastward up across the southern Plains within deeper layer southwest flow that is overlapping with a moist and strongly unstable boundary layer. MLCAPE values of as much as 3000 to 4000+ J/kg and PWs of 1.3 to 1.5 inches are in place east of the dryline, and this highly favorable thermodynamic environment coupled with as much as 40 kts of effective bulk shear should favor an environment conducive for organized convection going through the evening hours. Facilitating the convective sustenance this evening will also be at least some increase in a southerly low-level jet out ahead of the shortwave energy which will yield stronger moisture transport. This coupled with the strong instability will help drive the potential for increasing rainfall rates with the evolving convective clusters. Despite a notable threat for severe hazards including large hail, the convection over the next few hours should be characterized by some cell-mergers and thus consolidating supercells that will likely yield a larger scale MCS concern and resulting heavy rainfall threat. The downstream environment to the east of the current activity is more moist and unstable and capable of fostering high rainfall rates. Expect rainfall rates with the cell-mergers to be capable of reaching 2.5 inches/hour, and there will be some storm totals that will be capable of reaching 3 to 4 inches with isolated heavier amounts where any localized repeating/training of cells occur going through the evening. Some isolated instances of flash flooding will be possible as a result. Orrison ....Please see https://urldefense.com/v3/__http://www.wpc.ncep.noaa.gov__;!!= DZ3fjg!7jrcAV4FRIDW3eX3wD-WYqJygMBFmI40WwtRIGhzKDiDW6mmeUitVUZokdtIldEl_Lby= xAbbahc_ihpMyI8IegGfRi0$ for graphic product... ATTN...WFO...EWX...FWD...OUN...SJT... ATTN...RFC...ABRFC...WGRFC...NWC... LAT...LON 34099795 33949735 33519675 32889652 31809676=20 31149740 30979820 31149897 31459948 32379972=20 33099944 33879878=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) .