Subj : MESO: Nws Weather Prediction Center College Park Md To : wx-storm@lists.illinois.edu From : COD Weather Processor Date : Sat Feb 15 2025 17:02:22 AWUS01 KWNH 151701 FFGMPD VAZ000-WVZ000-152300- Mesoscale Precipitation Discussion 0039 NWS Weather Prediction Center College Park MD 1200 PM EST Sat Feb 15 2025 Areas affected...Central Appalachians and Portions of the VA Piedmont Concerning...Heavy rainfall...Flash flooding possible Valid 151700Z - 152300Z SUMMARY...Heavy rainfall moving into the central Appalachians and adjacent areas of the VA Piedmont coupled with areas of melting snow will set the stage for areal flooding and possible flash flooding going through the afternoon hours. DISCUSSION...The latest radar imagery shows moderate to heavy rainfall along with locally some mixed precipitation that is in the process of changing to rain advancing east across the central Appalachians with southern WV and southwest VA seeing generally the heaviest corridor of higher rainfall rates. The rainfall is associated with strong warm air advection and moisture transport into the region which is being aided by a southwest low-level jet of 40 to 50 kts. Instability is generally non-existent, but the level of isentropic ascent and low-level frontogenetical forcing is quite strong and is supporting rainfall rates of a 0.25" to 0.50"/hour. Meanwhile, heavier rains are noted locally upstream over areas of central and eastern KY which will be advancing eastward this afternoon, and with an additional strengthening of the low-level jet expected this afternoon, somewhat heavier rates that may exceed a 0.50"/hour will be possible over areas of southern WV down through southwest VA. Some very modest intrusion of elevated instability may arrive toward this evening that may also support a few thunderstorms capable of producing these heavier rates. The 12Z HREF guidance suggests additional rainfall amounts of as much as 1 to 2+ inches by early this evening. These rains coupled with warmer temperatures and a melting snowpack over some of the higher terrain, and already high streamflows, will favor an increasing concern for areal flooding and potentially some flash flooding where these heavier rainfall rates can focus and persist. Conditions will continue to be closely monitored over the next several hours. Orrison ....Please see https://urldefense.com/v3/__http://www.wpc.ncep.noaa.gov__;!!= DZ3fjg!9CXcnsAJgEF_8dcauc9YTCzQK2Ukg73QSPRiGtp6YqQvqygLqPd4dqwi8v6lfNypQH5a= JsyKzLS8e6_RN0Yz9pC3E8A$ for graphic product... ATTN...WFO...LWX...MRX...RLX...RNK... ATTN...RFC...LMRFC...MARFC...OHRFC...SERFC...NWC... LAT...LON 38808007 38567930 38127898 37597888 37007910=20 36707971 36598126 36708187 37698188 38258235=20 38578216 38798126=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 3.20-Linux * Origin: capitolcityonline.net * Telnet/SSH:2022/HTTP (1:2320/105) .