Flash Flood Guidance
Issued by NWS
Issued by NWS
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147 AWUS01 KWNH 241508 FFGMPD TNZ000-KYZ000-ALZ000-ILZ000-MSZ000-MOZ000-241900- Mesoscale Precipitation Discussion 0315 NWS Weather Prediction Center College Park MD 1107 AM EDT Fri May 24 2024 Areas affected...Portions of the Tennessee Valley Concerning...Heavy rainfall...Flash flooding likely Valid 241506Z - 241900Z SUMMARY...Influx of moisture on south-southwesterly flow is allowing storms across the Lower Ohio and Tennessee Valleys to backbuild. The storms have a history of over 2 inch per hour rainfall rates with the most persistent backbuilding. Ongoing and new flash flooding will continue into the afternoon. DISCUSSION...A line of convection that formed on the leading edge of a now dissipated MCS over Arkansas has been backbuilding this morning as 30-40 kt south-southwesterly flow at 850 mb injects moisture with PWATs over 1.5 inches into the storm complex. While individual cells have been moving, backbuilding and training of newly formed convection over the same areas has resulted in flash flooding over western Tennessee and northeastern Mississippi. Isolated pockets of 4 inches storm total rainfall have been analyzed by the Memphis radar along the line of storms. Backbuilding may continue into the early afternoon hours as the flow remains steady and additional moisture advects into the area. The influx of moisture into the back edge of the storms supports continued backbuilding/training. This is suggested by the latest HRRR and CONEST runs, though neither have been performing well with the evolution of the storms so far. With differential daytime heating, the complex should weaken with time albeit with significant disagreement on how long that will take. Wegman ...Please see www.wpc.ncep.noaa.gov for graphic product... ATTN...WFO...BMX...HUN...LSX...MEG...OHX...PAH... ATTN...RFC...LMRFC...NCRFC...OHRFC...SERFC...NWC... LAT...LON 37968846 37518788 36598807 36118779 35548721 34948705 33958701 33868778 34148859 34648881 35278910 35858940 36488975 36969000 37399022 37969020 37948919