Flash Flood Guidance
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Issued by NWS
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119 AWUS01 KWNH 301458 FFGMPD MSZ000-LAZ000-301900- Mesoscale Precipitation Discussion 0345 NWS Weather Prediction Center College Park MD 1057 AM EDT Thu May 30 2024 Areas affected...Lower MS Valley Concerning...Heavy rainfall...Flash flooding possible Valid 301455Z - 301900Z SUMMARY...Localized flash flooding will be possible across the Lower MS Valley into the early afternoon with slow moving thunderstorms capable of producing 2-3 in/hr rainfall rates. The threat is expected to diminish by 20Z. DISCUSSION...Radar/satellite imagery across the Lower MS Valley showed ongoing convection near a stationary front with an outflow boundary analyzed from just south of MCB, HEZ into northeastern LA. 14Z SPC mesoanalysis data showed a gradient in MLCAPE with 500-1000 J/kg just south of the ongoing thunderstorms, in association with the front/outflow boundary. In addition to low level flow overrunning the relatively cooler air to the north, an area of enhanced low level moisture transport was noted in the 925-850 mb layer over southwestern MS, converging near and south of I-20. MRMS indicated peak rainfall rates of 2-3 in/hr over the past few hours from southwestern MS into adjacent portions of LA. Thunderstorms are expected to continue over the next few hours with continued slow movement at times in the vicinity of the low level convergence axis. Short term RAP forecasts show weakening of the low level moisture transport and convergence axis through 20Z, which with the onset of peak heating, should disrupt the ongoing area of slow moving convection. However, until that happens, additional rainfall totals of 2-4 inches will be possible which may result in at least localized flash flooding from intense short term rainfall rates. Otto ...Please see www.wpc.ncep.noaa.gov for graphic product... ATTN...WFO...JAN...LCH...LIX...MOB...SHV... ATTN...RFC...LMRFC...NWC... LAT...LON 32579214 32079003 31628865 30818875 30699062 31499316 32419336