Flash Flood Guidance
Issued by NWS
Issued by NWS
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875 AWUS01 KWNH 262306 FFGMPD PAZ000-MDZ000-VAZ000-WVZ000-OHZ000-KYZ000-270500- Mesoscale Precipitation Discussion 0504 NWS Weather Prediction Center College Park MD 705 PM EDT Wed Jun 26 2024 Areas affected...Central Appalachians Concerning...Heavy rainfall...Flash flooding possible Valid 262304Z - 270500Z SUMMARY...An area of thunderstorms with training embedded cells ahead of an advancing cold front may cause flash flooding through this evening. DISCUSSION...An area of training storms (Round 1) that has developed on the upslope side of the central Appalachians across much of eastern West Virginia has embedded cells with rates approaching 2 inches per hour. This area of convection is over parts of West Virginia where FFGs are as low as 1.5 inches per hour. Thus, localized areas are seeing FFGs exceeded with the stronger storms. SBCape values in eastern West Virginia are up to 1,500 J/kg with PWATs to 1.7 inches according to SPC Mesoanalysis. This is enough instability and available moisture to sustain storms capable of producing flash flooding given the multiple sources of forcing for the storms. The cold front off to the north and west (Round 2) is producing storms with rates to 1.5 inches per hour across eastern Ohio. As the front moves into West Virginia over the next few hours, upslope flow off the terrain due to the northwesterly flow associated with the front and the cooler, drier air mass behind it will cause additional uplift along the terrain prior to the front moving through. This is expected to locally enhance rainfall rates over the same areas being hit with convection presently. Thus, localized flash flooding is possible, both with the current convection`s stronger cells along with any training, as well as with expected convection associated with the cold frontal passage late this evening. The cold front should be through the area by 05Z (1am), ending the flash flooding threat. Wegman ...Please see www.wpc.ncep.noaa.gov for graphic product... ATTN...WFO...CTP...JKL...LWX...PBZ...RLX...RNK... ATTN...RFC...LMRFC...MARFC...OHRFC...NWC... LAT...LON 40538026 40517940 40387899 39987832 38977849 37498009 37178144 37438275 38108228 39468122