Subj : MESO: Nws Weather Prediction Center College Park Md To : wx-storm@lists.illinois.edu From : COD Weather Processor Date : Sat Jun 01 2024 06:47:08 AWUS01 KWNH 010647 FFGMPD FLZ000-ALZ000-011245- Mesoscale Precipitation Discussion 0364 NWS Weather Prediction Center College Park MD 246 AM EDT Sat Jun 01 2024 Areas affected...Southern AL...Western FL Panhandle Concerning...Heavy rainfall...Flash flooding likely Valid 010645Z - 011245Z SUMMARY...A potentially high-impact and extreme rainfall event will be possible going through Saturday morning across portions of southern AL and the western FL Panhandle. Slow-moving showers and thunderstorms will be capable of training over the same area with extreme rainfall rates. Flash flooding is expected, with concerns for locally significant impacts given the setup. DISCUSSION...Extremely heavy showers and thunderstorms are expected to develop and expand in coverage across areas of southern AL and the western FL Panhandle over the next several hours as a well-defined shortwave trough and embedded vort center crosses the central Gulf Coast region and interacts with an extremely favorable environment for slow-moving convection and extreme rainfall rates. The environment across southern AL and the western FL Panhandle is tropical in nature with PWs of 1.8 to 2 inches, and the latest CIRA-ALPW products show a substantial concentration of moisture in the 850/500 mb layer. Of particular note though is the latest RAP analysis which shows a ribbon of moderate instability nosing northward off the Gulf of Mexico and inland across the central Gulf Coast region out ahead of this slow-moving shortwave energy, with MLCAPE values of 1000 to 2000 J/kg. Additionally, there is increasingly convergent 925/700 mb flow setting up from the northern Gulf of Mexico up into areas of southern AL. Already there are a few slow-moving clusters of convection that have developed, and GOES-E IR satellite imagery does show cooling convective tops over parts of southwest AL. Additional expansion of cold-topped convection is expected over the next several hours as the shortwave energy arriving fosters deeper layer ascent with highly divergent flow aloft coinciding with a further uptick in very moist and convergent low-level flow in off the northern Gulf of Mexico. Rainfall rates are forecast to reach 2 to 3 inches/hour with some of the more focused convective cores, and the environment will be conducive for localized back-building and training of convective cells that will foster serious concerns for extremely heavy rainfall totals. The 00Z HREF guidance is showing some low-end probabilities of rainfall exceeding the 100-year ARI in a 6-hour period by 12Z, but these probabilities increase to 20 to 30 percent in the 12 to 18Z time frame on Saturday. Rainfall amounts may locally reach 3 to 6 inches by 12Z, with additional excessive rains expected in a very concentrated manner after 12Z near the Gulf Coast. Flash flooding is expected with concerns for locally significant impacts given the extreme rainfall potential. Additional MPDs will be issued accordingly throughout the morning. Orrison ....Please see https://urldefense.com/v3/__http://www.wpc.ncep.noaa.gov__;!!= DZ3fjg!5myrmjtLELi46syKdpGiHEbgj58X2TLTdcCbP3vCh4CRjbG7Yaq0HEeQE607BpuRZty7= xUTGZ0-k3ciFG3gooVn7Q4o$ for graphic product... ATTN...WFO...BMX...MOB...TAE... ATTN...RFC...LMRFC...SERFC...NWC... LAT...LON 32078719 31898674 31628639 31268605 30598582=20 30238586 30318673 30298705 30228763 30478830=20 31298842 31818820 32068787=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) .