Subj : MESO: Nws Weather Prediction Center College Park Md To : wx-storm@lists.illinois.edu From : COD Weather Processor Date : Wed Jul 23 2025 23:58:19 AWUS01 KWNH 232357 FFGMPD FLZ000-GAZ000-ALZ000-240500- Mesoscale Precipitation Discussion 0788 NWS Weather Prediction Center College Park MD 756 PM EDT Wed Jul 23 2025 Areas affected...Florida Panhandle Concerning...Heavy rainfall...Flash flooding possible Valid 232356Z - 240500Z Summary...Thunderstorms developing along a stationary front will train to the west through this evening. Rainfall rates of 2-4"/hr, or briefly higher, are expected, which could produce 3-5" of rain. Flash flooding is possible. Discussion...The regional radar mosaic this evening indicates expanding and intensifying thunderstorms from the northern Florida Peninsula westward along much of the Florida Panhandle. These storms are developing along a stalled stationary front analyzed by WPC, which is oscillating subtly north and south in response to convective outflow boundaries from prior thunderstorms. A weak shortwave/MCV is noted in the WV imagery pushing off the Gulf Coast north of Tampa, while a surface wave tracks along the front itself. Together, this MCV and the surface low are helping to enhance E/NE flow off the Atlantic coasts of GA/SC, measured by 850mb wind speeds via VWPs of 20 kts. This E/NE low-level flow is advecting copious moisture westward, reflected by a plume of sfc-850mb LPW above the 99th percentile according to CIRA, which is helping to drive full-column PWs to above 2.6 inches as measured by GPS (likely convectively enhanced, but still well above daily records and indicative of the extreme environment in place.) Within this environment, rainfall rates of 6"/hr have been measured (1.5" in 15 mins) from WFO TAE. Over the past 1-2 hours, convection has expanded across the Florida Panhandle, and although the CAMs are generally in agreement with the evolution, the current coverage is greater than the simulated reflectivity from the guidance. As 850mb winds continue to impinge into the merged outflow boundary/stationary front, they will drive impressive convergence for ascent, with subtle height falls downstream of the MCV/shortwave contributing additionally. At the same time, overall forcing is weak and mean 0-6km winds are just 5 kts, so as the greater 850mb winds continue to track west they will increasingly exceed the mean flow to enhance ascent even further. This will likely manifest as widespread convection continuing for several more hours, with the intense local convergence tapping elevated MUCAPE of 3000 J/kg to support intense rainfall rates. The HREF neighborhood probabilities forecast the greatest potential for 2+"/hr rates to occur in the next 1-2 hours (locally 4+"/hr according to the HRRR), but the environment will likely support intense rainfall through at least 04Z. With light mean winds aligned to the front, and this front providing the primary focus for convective initiation, this could result in an axes of 3-5" of rain through the next few hours. FFG across the FL Panhandle is elevated at 4"/3hrs, but locally this has already been exceeded in some areas resulting in an isolated FFW from KJAX. Although HREF 3-hr FFG exceedance probabilities drop to just around 10-15% the next few hours, any training of these intense rain rates could overwhelm soils, leading to instances of flash flooding, but this will be most likely over more urban centers. Weiss ....Please see https://urldefense.com/v3/__http://www.wpc.ncep.noaa.gov__;!!= DZ3fjg!7K6zS66mfgpyMYnET_eZn9nav1kP307LY0UgzwUDtXPhMynVdr2WhbGLCKfRguUdzW2T= xdk0fgK-DWrT-VjCAuA5Nic$ for graphic product... ATTN...WFO...JAX...MOB...TAE...TBW... ATTN...RFC...ALR...NWC... LAT...LON 31358652 31258400 30938226 30308198 29628192=20 29108219 28958274 29198345 29378419 29448489=20 29668556 29908636 30038694 30358749 31118761=20 =20=20=20=20=20=20=20=20=20=20=20=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 3.28-Linux * Origin: capitolcityonline.net * Telnet/SSH:2022/HTTP (1:2320/105) .