Flash Flood Guidance
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Issued by NWS
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370 AWUS01 KWNH 060219 FFGMPD PAZ000-WVZ000-OHZ000-060616- Mesoscale Precipitation Discussion 0403 NWS Weather Prediction Center College Park MD 1019 PM EDT Wed Jun 05 2024 Areas affected...central/eastern Ohio, western Pennsylvania, northern West Virginia Concerning...Heavy rainfall...Flash flooding possible Valid 060216Z - 060616Z Summary...Deep convection was oriented favorably for localized training/cell mergers, resulting in estimated 1-1.5 inch/hr rain rates in spots. Flash flooding is possible as storms translate eastward across the southern half of Ohio through 04-05Z, with convection potentially reaching western Pennsylvania/northern West Virginia around/after that timeframe. Discussion...Broad low-level confluence both along and ahead of a surface front in Indiana was providing enough lift for scattered to numerous thunderstorms across central Ohio recently. The storms were organized as a series of both cells and small linear segments, with a focused axis of training/cell mergers noted near/north of Columbus. The storms were in an moist and sufficiently unstable environment for deep updrafts with efficient rainfall rates, which exceeded 1 inch/hr beneath the more persistently training storms in the area. These rain rates were approaching FFG thresholds of 1.5 inch/hr across the region, suggesting a continued, and at least isolated, flash flood threat in the short term. These cells will continue to shift eastward at approximately 15-25 mph, with slow movement and 1.7 inch PW values continuing to support efficient rainfall. Over time, some degree of boundary layer cooling is expected, although upper 60s to 70F dewpoints should maintain some degree of buoyancy to support deep convection over at least the next 3-4 hours. Potential exists for this activity to reach more sensitive ground conditions in eastern Ohio/western Pennsylvania beginning after 04Z or so. The flash flood scenario will be re-evaluated for any potential eastward persistence after 05Z. Cook ...Please see www.wpc.ncep.noaa.gov for graphic product... ATTN...WFO...CLE...ILN...PBZ...RLX... ATTN...RFC...OHRFC...NWC... LAT...LON 41108089 40708013 39998031 39298159 38938353 39928410 40588308