


Flash Flood Guidance
Issued by NWS
Issued by NWS
386 AWUS01 KWNH 070921 FFGMPD TNZ000-KYZ000-INZ000-ILZ000-MOZ000-071520- Mesoscale Precipitation Discussion 1165 NWS Weather Prediction Center College Park MD 520 AM EDT Tue Oct 07 2025 Areas affected...Portions of the Mid South and Lower Ohio Valley Concerning...Heavy rainfall...Flash flooding possible Valid 070920Z - 071520Z SUMMARY...Heavy rainfall still impacting portions of the Mid-South early this morning will become increasingly focused across the Lower OH Valley over the next several hours. Some isolated to scattered areas of flash flooding will be possible where any cell-training of showers and thunderstorms occur. DISCUSSION...A well-defined surface low and associated mid-level vort center is beginning to edge into the Lower OH Valley along with a pronounced surge of tropical moisture. A southerly low-level jet of 30 to 40 kts continues to focus rather strong warm air advection and moisture transport around the eastern flank of the low center, and this combined with modest instability and some upper-level jet divergence should support broken areas of heavy rainfall overspreading the Lower OH Valley this morning. MLCAPE values are only on the order of 500 to 750 J/kg, but the moisture convergence parameters are rather strong around the northeast flank of the vort energy and especially near the low center itself. This is favoring some stronger convective elements with highly efficient rainfall owing to warm rain/relatively shallow-topped convection. Some embedded colder convective tops are occurring in sporadic bursts, and these smaller scale clusters of convection have been capable of producing rainfall rates on the order of 1.5 to 2.5 inches/hour. As this energy begins lifting northeastward across the Lower OH Valley this morning, there is expected to be some gradual interaction with an upstream cold front approaching the OH Valley from the northwest. This will support a more frontogenetical component to the heavy rainfall threat and should support a more elongated southwest to northeast axis of heavy rain with embedded convection. The 00Z HREF/REFS suites of guidance support some localized swaths of 2 to 4+ inches of rain going through late this morning, with a spotty 5+ inch total not out of the question where any cell-training of convection occurs. The heavier and more concentrated areas of rainfall should be close to the OH River involving areas of far southeast IL, western and northwest KY and into far southern IN. Antecedent conditions across the region are generally on the dry side, but the rainfall potential this morning is expected to be enough to drive a threat for isolated to scattered areas of flash flooding. This will especially be the case in vicinity of the more urbanized areas. Orrison ...Please see www.wpc.ncep.noaa.gov for graphic product... ATTN...WFO...ILN...IND...JKL...LMK...MEG...OHX...PAH... ATTN...RFC...MSR...ORN...TIR...NWC... LAT...LON 39008471 38588377 37748383 37098453 36388586 36088694 36008780 35988834 36028894 36278967 36758973 37398939 38028844 38508736 38958580