Flash Flood Guidance
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Issued by NWS
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296 AWUS01 KWNH 061836 FFGMPD MDZ000-VAZ000-NCZ000-WVZ000-TNZ000-070030- Mesoscale Precipitation Discussion 0231 NWS Weather Prediction Center College Park MD 235 PM EDT Mon May 06 2024 Areas affected...Western Virginia and North Carolina Concerning...Heavy rainfall...Flash flooding possible Valid 061835Z - 070030Z SUMMARY...Thunderstorms associated with an advancing upper level shortwave are developing in a very unstable and moisture-rich environment across portions of the Mid-Atlantic. Flash flooding will be possible where multiple rounds of storms impact flood-sensitive areas. DISCUSSION...An area of thunderstorms associated with an upper level shortwave trough is moving east into the Mid-Atlantic this afternoon. The storms are moving into an environment characterized by PWATs up to 1.75 inches across eastern Virginia and North Carolina, and SBCAPE values as high as 2,500 J/kg based on SPC Mesoanalysis. The storms that have formed so far have produced local rainfall rates up to 2.5 inches per hour. Some clearing over central Virginia has allowed for instability to rapidly increase in the moisture rich environment. More isolated thunderstorms have developed ahead of the main area of storms. These storms have been slow-moving, and locally increase the potential for flash flooding as additional storms follow behind the ones ahead of the line. As the storms approach a boundary over northern Virginia in the next few hours, they are expected to develop into an east-west oriented line, likely over central Virginia south of the boundary. CAMs are in reasonable agreement as to this new line of storms developing. As additional storms run into the boundary over Northern Virginia, training storms will become more likely. While this area has been relatively dry compared to areas further north towards DC and its Virginia suburbs, rates up to 2.5 inches per hour could cause localized flash flooding into this evening as the heavy rainfall overwhelms local watersheds. Wegman ...Please see www.wpc.ncep.noaa.gov for graphic product... ATTN...WFO...AKQ...GSP...LWX...MRX...RAH...RLX...RNK... ATTN...RFC...LMRFC...MARFC...OHRFC...SERFC...NWC... LAT...LON 38897915 38857828 38837795 38757759 38597709 37937688 37267752 36407860 36157954 35368182 36478166 37098193 37568192 38438066