####018002625#### AWUS01 KWNH 151840 FFGMPD VAZ000-WVZ000-160015- Mesoscale Precipitation Discussion 0273 NWS Weather Prediction Center College Park MD 239 PM EDT Thu May 15 2025 Areas affected...eastern WV into western VA Concerning...Heavy rainfall...Flash flooding possible Valid 151838Z - 160015Z Summary...Showers and thunderstorms are expected to develop over the higher terrain of eastern WV into western VA within the next 1-3 hours. While movement of cells should be generally progressive, exceedance of very low flash flood guidance (FFG) may result in spotty runoff issues atop sensitive grounds. Discussion...Visible satellite imagery at 1815Z showed an expanding field of cumulus with increasing vertical development over the central Appalachians of eastern WV to the Blue Ridge Mountains of western VA. This region was located behind a departing mid to upper-level trough over the northern Mid-Atlantic coast within a WNW flow aloft. While the deeper moisture axis was located over the western Atlantic, weakly anomalous precipitable water (PW) values of approximately 1.0 to 1.3 inches remained via area GPS PWs and a special 17Z sounding from RNK, with some contribution to the low to mid-level layer coming from the southwest via LPW imagery. Daytime heating has also contributed to 500 to ~1500 J/kg MLCAPE across the region via SPC mesoanalysis data and the RNK sounding. Continued heating of the elevated heat source(s) will likely contribute to convective initiation within the next 1-3 hours, based on satellite trends and short term RRFS/HRRR forecasts. Effective bulk shear values of 35 to 45 kt combined with the instability values should support some organized cells, capable of higher rainfall efficiency. Individual cell motions are expected to be fairly progressive toward the E to SE at 15-25 kt, but potential for 0.5 to 1.0 in/hr rates will exist and considering potential for mergers (perhaps slightly higher rates) could yield 1-2 inches through 00Z. While this is not a typical flash flood setup for the region, conditions on the ground are hyper-sensitive due to recent heavy rain with FFG values as low as 0.25 to 0.5 inches in an hour in some locations, with much of the outlooked area containing FFG below 1 in/hr. Otto ...Please see www.wpc.ncep.noaa.gov for graphic product... ATTN...WFO...AKQ...LWX...PBZ...RLX...RNK... ATTN...RFC...MARFC...OHRFC...SERFC...NWC... LAT...LON 39187838 38867798 37887823 37307895 37328029 37688069 38248069 38728009 39077944 ####018000679#### PENA01 KWNH 151200 @UHPISF000CN MPDSUM@V2.0@0101700060@12150525@@0NMCGPHMPD i@!' `' ` @ & B7)p&PNAM02@@$U|||z{{z{{|}}~~@@U@@U@@0273 @@d&MESOSCALE DISCUSSION SUMMARY GRAPHIC @@d& OF ALL VALID MESOSCALE DISCUSSIONS AT @@d& TIME OF PRODUCT CREATION:@@d& ISSUED 05/15/2025 1839Z @@ dNOAA/NWS/NCEP@@d WEATHER PREDICTION CENTER @@d FOR COLOR VERSION SEE: @@d WWW.WPC.NCEP.NOAA.GOV @