Subj : MESO: Nws Weather Prediction Center College Park Md To : wx-storm@lists.illinois.edu From : COD Weather Processor Date : Sun Dec 17 2023 07:05:38 AWUS01 KWNH 170705 FFGMPD SCZ000-FLZ000-GAZ000-171300- Mesoscale Precipitation Discussion 1201 NWS Weather Prediction Center College Park MD 204 AM EST Sun Dec 17 2023 Areas affected...much of Florida and southern through southeastern Georgia Concerning...Heavy rainfall...Flash flooding possible Valid 170703Z - 171300Z Summary...Widespread areas of moderate to heavy rain are expected to potentially cause localized flash flooding through 13Z. This potential will be higher where heavier rainfall can occur atop urbanized areas and/or areas that have experienced 2+ inch storm total rainfall - especially across central and northern Florida. Discussion...A sub-1000mb low continues to quickly deepen over northeastern Gulf of Mexico waters approximately 90 miles west-northwest of PIE/Pinellas County, FL. To the east of that low, ascent along and north of a warm front has allowed for multiple hours of ~0.25-0.75 inch/hr rain rates across central and northern Florida generally from I-4 northward to I-10. These rates have resulted in 2-4 inch storm totals, wetting soils while prompting potential for mainly minor, isolated flash flooding in the short term. Meanwhile south of this area, a warm front was advancing northward in tandem with the deepening low and extended from west to east very near I-4 (PIE to MLB). Along and south of this boundary, more isolated, but deeper convection has materialized in response to stronger instability (around 500-1000 J/kg over land - higher over water). The stronger convection has resulted in more isolated, but heavier rain rates exceeding 1 inch/hr at times.=20 Some concern exists that heavier convection near/northwest of Tampa could migrate northward toward the regions that have experienced heavier rainfall and wet soils so far tonight (closer to Ocala/Gainesville) and result in a brief increase in flash flood potential over the next 2-4 hours. An additional area of concern is for isolated heavier rainfall to materialize with scattered convection over populated areas in southeastern Florida. One cluster of storms recently produced an estimated 1-1.5 inch/hr rain rates just west of Miami/Dade Metro, and the urbanized nature of ground conditions in that area could lead to spots of flash flooding through 13Z. Overall, the entire regime is expected to continue to translate northward in conjunction with the deepening low over the Gulf and warm front over central Florida. Flash flood potential will increase toward northeastern Florida and southeastern Georgia over time - especially in the 09-13Z timeframe. Cook ....Please see https://urldefense.com/v3/__http://www.wpc.ncep.noaa.gov__;!!= DZ3fjg!4Xho0aGGiRzgjLm8YB-SAkbhIgtUuvi_QyAKC3IwdIofn0bJtH1io5l7um7mHmB8aSKA= fMYABk4JsG4FpaHp8E89A1U$ for graphic product... ATTN...WFO...CHS...FFC...JAX...MFL...MLB...TAE...TBW... ATTN...RFC...SERFC...NWC... LAT...LON 32118226 32118096 30988123 29108087 26607978=20 25618020 26168059 27378182 27838288 28908327=20 29998400 31028363=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) .