


Flash Flood Guidance
Issued by NWS
Issued by NWS
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063 AWUS01 KWNH 132211 FFGMPD OHZ000-KYZ000-INZ000-ILZ000-140410- Mesoscale Precipitation Discussion 0675 NWS Weather Prediction Center College Park MD 610 PM EDT Sun Jul 13 2025 Areas affected...Portions of the OH Valley Concerning...Heavy rainfall...Flash flooding possible Valid 132210Z - 140410Z SUMMARY...Heavy showers and thunderstorms will continue to impact portions of the OH Valley going through the evening hours. Isolated to scattered areas of flash flooding will continue to be possible, and especially around the more urbanized locations. DISCUSSION...GOES-E IR satellite imagery shows cold convective tops associated with heavy showers and thunderstorms across southeast IL and portions of central and southern IN. The activity remains focused ahead of a well-defined mid-level vort center/shortwave trough and an accompanying area of surface low pressure which is transiting a frontal zone. MLCAPE values over the Lower OH Valley are generally on the order of 1500 to 2500 J/kg, and this coupled with anomalous PWs of 2.0 to 2.25 inches will continue to favor very high rainfall rates that will be capable of reaching 2 to 3 inches/hour. Generally the convection should continue to advance off to the east, but there will be some relatively slow cell-motions, and pockets of localized cell-training and cell-merger activity that may allow for some rainfall totals to reach as high as 3 to 4+ inches by late this evening. This is supported by a consensus of the 18Z HREF and 12Z REFS guidance. However, the latest hires guidance does appear to be a bit slow with the overall downstream convective evolution. Based on the latest satellite and radar trends, convection should advance across southern IN and into western OH by late-evening. Given the high rainfall rates and localized concerns for cell-training, isolated to scattered areas of flash flooding will continue to be possible. This will include concerns for the more sensitive urbanized locations. Orrison ...Please see www.wpc.ncep.noaa.gov for graphic product... ATTN...WFO...CLE...ILN...ILX...IND...IWX...LMK...LSX...PAH... ATTN...RFC...MSR...TIR...NWC... LAT...LON 40928345 40288258 39458270 38548417 37838724 38068854 38868916 39688827 40588572