Subj : MESO: Nws Weather Prediction Center College Park Md To : wx-storm@lists.illinois.edu From : COD Weather Processor Date : Wed Aug 07 2024 22:52:58 AWUS01 KWNH 072252 FFGMPD MDZ000-VAZ000-WVZ000-OHZ000-KYZ000-080430- Mesoscale Precipitation Discussion 0830 NWS Weather Prediction Center College Park MD 652 PM EDT Wed Aug 07 2024 Areas affected...Western MD...Northwest VA...Much of WV...Eastern KY... Concerning...Heavy rainfall...Flash flooding possible Valid 072250Z - 080430Z SUMMARY...Moist unstable air pooled along a frontal zone through rugged terrain continues to support scattered to widely scattered highly efficient, slow moving thunderstorms capable of producing 1.5-2"/hr and an isolated spot up to 3" through early overnight period may be possible, resulting in localized possible flash flooding. DISCUSSION...22z surface analysis denotes a weak surface low in western KY a stationary front extending across central WV into Maryland. Stronger thunderstorms are starting to expand in coverage/cooling in tops across central WV. Tds in the low 70s and total PWats are nearing 2.0" which is well above average, leading edge of moisture associated with Debby has been starting to filter in through depth especially closer to the front where some sort of north to south oriented boundary, perhaps outflow, perhaps Bay Breeze assisted but nonetheless starting to flux into the upslope portions of NW VA into E VA. Concurrently, visible imagery shows weakening cu fields but confluent streets could be seen into the deeper frontal boundary reaching these well above average values. While insolation is reducing, the affects of heating remain with solid instability remaining to support the ongoing convection and potentially newer development given stronger approaching low level forcing.=20=20 As such, a few cells are starting to become clusters with overshooting tops cycling with occasional tops to -60C mainly across the western high slopes of western WV. While weak convergence has supported initial development, colliding outflow boundaries will help to maintain/expand as the cell seek out the remaining unstable air. CAPEs of 2000-25000 J/kg will fade to 1500 J/kg after night fall, but with strengthening flux, similar intense efficient rainfall producing thunderstorms will produce 1.5-2"/hr totals and given those occasional mergers/collisions could support a highly focused 3" total for the next few hours.=20 Given complex terrain, naturally lower FFG values of 1.5-2"/hr and 2-2.5"/3hrs, even into E KY there will remain a possibility of widely scattered incidents of flash flooding tonight.=20 Gallina ....Please see https://urldefense.com/v3/__http://www.wpc.ncep.noaa.gov__;!!= DZ3fjg!9XnGMDLsqizGgtYv8tMv3F-o6BGkFDZXn4hvSh9kire7vYWXGoT5tgb6kYq9n-n07xgy= JoRko3B3LIVqjTEUiDiTlqU$ for graphic product... ATTN...WFO...JKL...LWX...PBZ...RLX... ATTN...RFC...MARFC...OHRFC...NWC... LAT...LON 39627978 39597779 38997760 38527851 38208092=20 37938143 37188284 37338377 37948372 38608262=20 39498127=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) .