Subj : MESO: Nws Weather Prediction Center College Park Md To : wx-storm@lists.illinois.edu From : COD Weather Processor Date : Tue Jun 20 2023 14:16:16 AWUS01 KWNH 201416 FFGMPD FLZ000-201810- Mesoscale Precipitation Discussion 0537 NWS Weather Prediction Center College Park MD 1015 AM EDT Tue Jun 20 2023 Areas affected...North FL and portions of the Nature Coast Concerning...Heavy rainfall...Flash flooding possible Valid 201410Z - 201810Z DISCUSSION...Training convection across northern FL has redeveloped and may lead to isolated flash flooding for parts of northern FL and southern parts of the Nature Coast. SUMMARY...Ongoing convection along a east-west oriented outflow boundary has led to redeveloped convection impacting areas specifically near Ocala, FL. Instantaneous rainfall rates are noted as high as 4"/hr from MRMS, which has also led to elevated FLASH CREST unit streamflow over 400 cfs/smi within the areas of heaviest convection. These values depict rapid ponding of water is possible over the mostly flat terrain, with urban flooding near impervious surfaces. Precipitable water values of 1.9-2.0" are noted along this leading outflow boundary/surface trough ahead of a cold front over the Southeast. This boundary loops back into the northeast Gulf of Mexico, which is parallel to the mean-layer winds, providing an additional source of upstream moisture. HRRR guidance has struggled to maintain convection as area of thunderstorms gradually sink southward. Even so, the 12z HRRR depicts 1-hr QPF exceeding 2" near Crystal River and nearby areas of the southern Nature Coast through noon, with scattered thunderstorms possibly lingering shortly afterwards. While the ongoing convection is expected to slide south of its current location, additional instances of intense rainfall are expected to lead to a threat of flash flooding should it overlap with urbanized regions. Portions north of Ocala, FL have experienced prior 3-4"+ amounts and could see renewed flood chances should the redeveloping convection inch north of the expected forecast. Snell ....Please see https://urldefense.com/v3/__http://www.wpc.ncep.noaa.gov__;!!= DZ3fjg!7qr-_5s1-MqEGyG2mKLeDaLeoYodNOT8LXzQuRotx7wv8DEX-6Dn25tc5JNxFILRdwIp= IVNUpgagm7DaWBcT4T1AOrE$ for graphic product... ATTN...WFO...JAX...MLB...TAE...TBW... ATTN...RFC...SERFC...NWC... LAT...LON 29548278 29508229 29268190 28868185 28688223=20 28798281 29138311 29408302=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) .