Subj : MESO: Nws Weather Prediction Center College Park Md To : wx-storm@lists.illinois.edu From : COD Weather Processor Date : Mon Mar 27 2023 02:18:50 AWUS01 KWNH 270218 FFGMPD SCZ000-GAZ000-270730- Mesoscale Precipitation Discussion 0136 NWS Weather Prediction Center College Park MD 1018 PM EDT Sun Mar 26 2023 Areas affected...East-central GA... West-central SC... Concerning...Heavy rainfall...Flash flooding likely Valid 270215Z - 270730Z SUMMARY...Initially slow moving thunderstorms along the warm front pose localized flash flooding risk before upstream cells arrive producing training/mergers and continuing flash flooding risk through early morning hours. DISCUSSION...GOES-E IR depicts overshooting tops breaking through the cirrus debris from larger upstream complex. These widely scattered to scattered thunderstorms are developing along the preceding pressure trof where sfc winds have backed slightly with fairly solid confluence across central SC into eastern GA. This generally aligns with a step increase of low level moisture where Tds increase to mid-60s and may be considered the edge of the warm front, even though upstream height-falls have lead to southern winds and increasing Tds across the Upstate as well. This is also aligned with increasingly unidirectional flow per VWP at JGX and FFC out of the southwest at 25-30kts. This higher theta-E air aloft, still has sufficient buoyancy for 500-1000 J/kg and 1.3 to 1.5" total PWats to allow for efficient rainfall production.=20 Rates of 1.5-2"/hr are probable within the regime. Currently, steering flow is unidirectional to support a favorable training environment to wash over the region in the next few hours as greater convective coverage associated with subtle shortwave reaches the area. However, the backed low level flow and approaching height-falls has supported a col in the flow to allow for slower cell motions, particularly even weak rotating updrafts in the vicinity. This will allow for increased duration of these efficient rates and has the potential for 2-3" totals in the short-term period and widely scattered incidents of flash flooding. Given early morning thunderstorms with 1-3" totals from Putnam, GA to Aiken/Lexington, SC have compromised soils flash flooding is considered likely as FFG values have been compromised to well less than 1.5"/hr and 2.5"/3hrs. Flash flooding incidents are going increase in probability from west to east as the areal coverage of stronger updrafts become numerous while also likely to train/repeat through the same axis along and north of the trof axis/frontal zone. Additional 2-3" totals may result in isolated spots of 4" and flash flooding will continue to be likely especially along the compromised soil axis/Fall Line. Gallina ....Please see https://urldefense.com/v3/__http://www.wpc.ncep.noaa.gov__;!!= DZ3fjg!-H-SOWqxet58O_3O84f6Ie4OXocRt3QwNhnw2Ic1Kw4LcGyZcl20iIBsC05Ss9ImKKgB= 1zAtuYXTeieDLYXEi5kxvqc$ for graphic product... ATTN...WFO...CAE...FFC...GSP... ATTN...RFC...SERFC...NWC... LAT...LON 34718115 34588037 33888024 33418125 33048218=20 32918305 32898377 33728407 34098398 34398322=20 34578221=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) .