Subj : MESO: Nws Weather Prediction Center College Park Md To : wx-storm@lists.illinois.edu From : COD Weather Processor Date : Sun Sep 03 2023 07:00:15 AWUS01 KWNH 030700 FFGMPD FLZ000-ALZ000-MSZ000-LAZ000-031255- Mesoscale Precipitation Discussion 1028 NWS Weather Prediction Center College Park MD 259 AM EDT Sun Sep 03 2023 Areas affected...Central Gulf Coast Concerning...Heavy rainfall...Flash flooding possible Valid 030657Z - 031255Z Summary...Isolated flash flooding along portions of the central Gulf Coast will be possible through 13Z. High rainfall rates of 1-2 inches in 30 minutes will be possible but coverage of these higher rain rates should stay highly localized. Discussion...Recent local radar imagery from KMOB and KEVX showed a few warm-topped showers along and just offshore of the coast of the western FL Panhandle and barrier islands south of MS/AL. 06Z surface observations identified a weakly defined frontal boundary from west to east along the central Gulf Coast, marked by surface winds with a southerly component south of the boundary and east to northeasterly winds for locations just north of the boundary. A tight gradient in SB and MLCAPE existed along the convergence axis with less than 500 J/kg to the north but over 1000 J/kg to the immediate south of the boundary and over the open Gulf waters as seen on the 06Z SPC mesoanalysis. There was little to no low level CIN present in RAP analysis soundings along the surface front and precipitable water values from GPS sensors and GOES East derived imagery indicated values ranging between 2.0 and 2.3 inches in the vicinity of the central Gulf Coast. This environment will be supportive of efficient rainfall with potential for 1-2 inches of rain in 15-30 minutes. Widely scattered showers and perhaps a thunderstorm will be possible along the Gulf Coast from MS, AL into the western FL Panhandle, just west of an upper ridge centered south of Apalachicola, FL. Localized showers are expected to continue over the next few hours where weak low level convergence within the unstable environment is able to force ascent within the tropical airmass in place. Slow steering flow from the south to southeast matches the orientation of low level inflow, which will favor training from south to north or southeast to northwest. High rainfall rates with localized rainfall totals of 3 to 5+ inches will be possible, but coverage will likely remain very limited if these totals are able to materialize. Given high FFG values along the coast, flash flooding will be limited to urban areas or other locations with poor drainage. Otto ....Please see https://urldefense.com/v3/__http://www.wpc.ncep.noaa.gov__;!!= DZ3fjg!4XSpH6SPx3dfZB6j9lpyxipEBNPua-oCC-lOVsJjk6ptQebx4bKmJWICnStiZh_GKyhZ= C0ID8ERc9nKp4NFyh-hzHac$ for graphic product... ATTN...WFO...LIX...MOB...TAE... ATTN...RFC...LMRFC...SERFC...NWC... LAT...LON 30728834 30648756 30628662 30298592 30038573=20 29918588 29958624 30088665 30098721 30078774=20 29978859 30098969 30328997 30548993 30668966=20 30668908=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) .