Flash Flood Guidance
Issued by NWS
Issued by NWS
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688 AWUS01 KWNH 010140 FFGMPD OKZ000-KSZ000-010735- Mesoscale Precipitation Discussion 0202 NWS Weather Prediction Center College Park MD 939 PM EDT Tue Apr 30 2024 Areas affected...northeastern OK...southeastern KS Concerning...Heavy rainfall...Flash flooding possible Valid 010135Z - 010735Z Summary...Localized totals of 2-4" may result in isolated to scattered instances of flash flooding. Discussion...A vigorous line of thunderstorms has organized rapidly this evening across southeast KS, just ahead of a dry line/cold front intersection with an associated low pressure system located just to the north (near Topeka). In the area of interest, the mesoscale environment is characterized by ML CAPE of 2000-3000 J/kg, PWATs of 1.1-1.3 inches (between the 75th and 90th percentile, per SPC sounding climatology), and deep layer (0-6km) shear of 30-40 kts. Strong southerly low-level moisture transport is ongoing into the region, resulting in very high moisture flux convergence and continued growth in the organizing convective system. As the front/dry line hang back to the west across central KS/OK, this will allow for localized training as the (850-300 mb) mean wind supports general storm movement towards the east (with backbuilding being the main mechanism for training). The HRRR depicted the potential for this localized training for many runs this afternoon (but has backed off a bit on the idea closer to 00z), which was reflected in the HREF neighborhood probabilities for 3" exceedance (as high as 20-30% through 06z). Although there is not a lot of CAM support anything more than localized flash flooding, the radar and satellite presentation have become quite impressive and the trends support localized totals of 2-4" developing. Idealized training of convection may result in scattered instances of flash flooding. Churchill ...Please see www.wpc.ncep.noaa.gov for graphic product... ATTN...WFO...ICT...OUN...SGF...TSA... ATTN...RFC...ABRFC...NWC... LAT...LON 37739580 37739543 37479472 36519467 36049502 36349721 36559782 37009810 37389726 37539644