Subj : MESO: Nws Weather Prediction Center College Park Md To : wx-storm@lists.illinois.edu From : COD Weather Processor Date : Thu Jun 22 2023 14:52:29 AWUS01 KWNH 221452 FFGMPD FLZ000-222100- Mesoscale Precipitation Discussion 0560 NWS Weather Prediction Center College Park MD 1051 AM EDT Thu Jun 22 2023 Areas affected...FL Big Bend and North FL Concerning...Heavy rainfall...Flash flooding possible Valid 221500Z - 222100Z SUMMARY...Additional west-east oriented convection moving onshore the Florida Big Bend and Nature Coast through the afternoon hours will present the potential for flash flooding. DISCUSSION...Regional radar mosaic and GOES-East visible satellite imagery depicts an outflow boundary/surface inflection stretching from the northern FL Peninsula to the northern Gulf of Mexico. Along this boundary areas of isolated convection exist over the limited instability environment overland, with more organized linear convection over the northeast Gulf of Mexico nearby coastal regions. Already this morning, over 5" of rainfall was estimated to have fallen over coastal sections of the Big Bend south-southwest of Perry, FL. Additionally, a much larger footprint of 3-5"+ amounts has occurred over the last 24 hours throughout the Big Bend and into parts of the northern FL Peninsula. These recent rainfall totals are likely to lower the usually high FFG across this part of the country. The ongoing west-east oriented convection extending from Apalachicola Bay to the northern Gulf of Mexico is anticipated to continue on an easterly track and along the mostly uniform westerly 850-300 mb flow. As the activity moves eastward, it is likely to turn slightly southward and along a better instability gradient set up due to a fairly stable airmass over far north-central FL associated with prior rainfall and thick cloud-cover. PWs are around 2" in the area and continued advection from the Gulf of Mexico will help maintain a moisture source for convection through 21z. Instability will also continue to be advected northeastward, with >2000 J/kg MLCAPE lingering right along the coast and over the northeast Gulf of Mexico. Localized rainfall rates up to 3"/hr are likely and could lead to new rainfall amounts of 3-5" through 21z. As previously mentioned, this area of the country is usually pretty hard to flash flood given the swampy terrain and will limit the potential impacts. However, any urban regions or low-lying areas will see the greatest chances for localized flash flooding. Snell ....Please see https://urldefense.com/v3/__http://www.wpc.ncep.noaa.gov__;!!= DZ3fjg!6GF1mb6uFpjNqOq-L4bTRZv67fbdU_d7Z5xz9RWvU7BrLgB5uR1e8dOZg__w1lnl5WB_= 5k3ssRXNBALkevjXno4R2Qo$ for graphic product... ATTN...WFO...JAX...TAE...TBW... ATTN...RFC...SERFC...NWC... LAT...LON 30328306 29958224 29338182 28878211 28868276=20 29468353 29658419 29528502 29698539 29988490=20 30288396=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) .