Subj : MESO: Nws Weather Prediction Center College Park Md To : wx-storm@lists.illinois.edu From : COD Weather Processor Date : Mon Mar 27 2023 16:54:35 AWUS01 KWNH 271654 FFGMPD FLZ000-GAZ000-ALZ000-272252- Mesoscale Precipitation Discussion 0140 NWS Weather Prediction Center College Park MD 1253 PM EDT Mon Mar 27 2023 Areas affected...Southeast AL...Portions of the Western FL Panhandle...Far Southwest GA Concerning...Heavy rainfall...Flash flooding possible Valid 271652Z - 272252Z SUMMARY...Slow-moving showers and thunderstorms, with some occasional training of cells, may produce sufficient rainfall amounts for a localized flash flood threat going through the afternoon hours. DISCUSSION...Radar and satellite imagery shows a gradual uptick in the coverage of shower and thunderstorm activity across southern AL as diurnal heating along with a moist boundary layer contributes to an increase in instability across the region. MLCAPE values of 1500+ J/kg are in place, and areas of southeast AL in particular have seen the greatest 3-hourly differential going through 15Z and 16Z. PWs across the region are as high as 1.5 to 1.7 inches and this coupled with the instability parameters have already favored rainfall rates of up to 2 inches/hour. Given the relatively confluent flow also in off the northern Gulf of Mexico, the expectation is for moisture and instability to become a bit more focused/concentrated across areas of southeast AL, far southwest GA, and potentially into far western areas of the FL Panhandle going through 21Z and then into the early evening hours. A cold front is also slowly approaching from the northwest, and the latest RAP analysis does show a fairly strong axis of moisture convergence situated along and just ahead of it. There are sufficient levels of vertical shear in conjunction with the available instability to promote additional areas of at least loosely organized convection going through the afternoon hours. The alignment of this with the west-southwest mean layer flow aloft will favor at least some transient concerns for some cell-training going through the afternoon hours. Expect concerns for locally an additional 2 to 4+ inches of rain where cells tend to train over the same area over the next several hours. It should be noted that recent HRRR runs actually support even heavier totals going into the early evening hours along the AL/FL border, so this will need to be monitored closely. Given that some locations in especially southeast AL saw heavy rain yesterday, these additional totals may result in at least a localized threat of flash flooding. Orrison ....Please see https://urldefense.com/v3/__http://www.wpc.ncep.noaa.gov__;!!= DZ3fjg!-nua5CTqaB4y5KE-DbPF2fSpB2rk4nVvWt6yq7RkzLGeqNkQxTwuBgv4HSAk2mpLbiWf= r8T2OlZ4VS6FpvsLacoOy3U$ for graphic product... ATTN...WFO...BMX...MOB...TAE... ATTN...RFC...SERFC...NWC... LAT...LON 31808487 31378450 30968473 30738563 30808656=20 31108699 31478673 31788582=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) .