Subj : MESO: Nws Weather Prediction Center College Park Md To : wx-storm@lists.illinois.edu From : COD Weather Processor Date : Mon Jun 19 2023 14:21:43 AWUS01 KWNH 191421 FFGMPD FLZ000-GAZ000-ALZ000-MSZ000-192000- Mesoscale Precipitation Discussion 0524 NWS Weather Prediction Center College Park MD 1020 AM EDT Mon Jun 19 2023 Areas affected...FL Panhandle...Southern GA...Southern AL...Southern MS Concerning...Heavy rainfall...Flash flooding possible Valid 191420Z - 192000Z SUMMARY...Repeated rounds of vigorous thunderstorms may produce maximum hourly rainfall rates as high as 2.5-3.0"/hr and could result in additional areas of flash flooding today. DISCUSSION...GOES-16 water vapor imagery showed the lead line of thunderstorms racing east through southern GA and the FL Panhandle with trailing thunderstorms along I-10 near the AL/MS border. The environment remains highly favorable for thunderstorms to produce efficient warm rain processes. The 12Z TLH sounding measured a 2.02" PWAT with 1,200 J/kg of MLCAPE with an impressive 40 knots worth of sfc-6km vertical wind shear to work with. The environment is even more unstable and contains better vertical wind shear in eastern LA as the 12Z LIX sounding had close to 4,000 J/kg of MLCAPE and 43 knots of sfc-6km vertical wind shear. These wind shear values are well above the 90th climatological percentile for this time of year. Lastly, dew points are as high as 80 degrees along the Gulf Coast in some locations. This highly unstable environment will be advected east into southern AL, the FL Panhandle, and southern GA today while 850-300mb flow runs parallel to trailing convection along the coast. With no capping present for much of the highlighted area, it will not take much surface based heating for more storms to flare up along the Gulf Coast this morning. The storms will also benefit from being in an environment that will have as much as 100-200 m2/s2 of sfc-1km SRH, fostering an air-mass that is conducive to mesocyclone formation. Mesocyclones in an air-mass with warm cloud layers as deep as 13,000 feet AGL are exceptional precipitation producers. Storms should be fast moving given the 25 knots of 850-300mb mean winds, but the prolonged westerly moisture transport favors additional thunderstorm development over areas that also feature overly saturated soils. AHPS 7-day rainfall totals are as high as 600% of normal in southern AL, southern GA, and between Mobile and Pensacola. Additional flash flooding is possible today within the highlighted area with urbanized communities, poor drainage areas, and sensitive soils most at-risk. Mullinax ....Please see https://urldefense.com/v3/__http://www.wpc.ncep.noaa.gov__;!!= DZ3fjg!4XOIjOJ3sG5il8CfFYcAsGJe0HW-NQtXRB0ulW7OihND7Tb-U7HbGr_i_LVaM2dPCoO9= XmpbD8ng6R4uq_hy7Cwh5nc$ for graphic product... ATTN...WFO...BMX...FFC...JAN...LIX...MOB...TAE... ATTN...RFC...LMRFC...SERFC...NWC... LAT...LON 32368540 32048429 31038398 29898433 29538515=20 30018636 30078779 30228946 31338976 31888837=20 32108711=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) .