Subj : MESO: Nws Weather Prediction Center College Park Md To : wx-storm@lists.illinois.edu From : COD Weather Processor Date : Fri Apr 26 2024 15:28:45 AWUS01 KWNH 261528 FFGMPD MOZ000-ARZ000-OKZ000-262040- Mesoscale Precipitation Discussion 0176 NWS Weather Prediction Center College Park MD 1127 AM EDT Fri Apr 26 2024 Areas affected...eastern OK into northwestern AR and southwestern MO Concerning...Heavy rainfall...Flash flooding possible Valid 261526Z - 262040Z SUMMARY...Localized areas of training may support additional heavy rainfall rates with 1-2 in/hr impacting portions of eastern OK into northwestern AR and southwestern MO through ~20Z. Given wet antecedent conditions in portions of the region, flash flooding will be possible. DISCUSSION...At 15Z, convection, much of it elevated, continued to stretch from eastern OK into northwestern AR and southwestern MO, with the northern portion showing more progressive movement toward the east than the portion farther south into OK. The thunderstorms were located along and north of a warm/stationary front that extended eastward through eastern OK into central AR where the 15Z SPC mesoanalysis indicated 500-1000 J/kg MUCAPE in place. Farther south, breaks in cloud cover were beginning to appear on visible satellite imagery, which should allow for surface heating and a weakening of MLCIN across locations south of the warm/stationary front. Also of note, an outflow boundary was located at the leading edge of the rain shield moving through AR into southeastern OK, with low level southerly flow overrunning the boundary, but better isentropic ascent was occurring farther north, ahead of the warm/stationary front. Coupled with the low level ascent was a a notable region of upper level diffluence centered over southwestern MO along with smaller scale regions of jet-influenced upper level divergence. With deeper-layer winds oriented from the southwest, or roughly parallel to the slower moving leading edge of precipitation, additional convective development along the southwestern flank is likely to train...at least temporarily...allowing for 1-2 in/hr rates and an additional 2-4 inches through ~20Z. Precipitable water values near 1.5 inches and sufficient instability will allow the flash flood threat to linger across the region over the next 3-5 hours. Adding to the threat, especially for locations in southwestern MO, is wet antecedent soils where an estimated 2 to 6 inches of rain has fallen over the past 24 hours. Flash flooding will remain possible for these locations through at least 20Z. Otto ....Please see https://urldefense.com/v3/__http://www.wpc.ncep.noaa.gov__;!!= DZ3fjg!7QmDn8HolRzq9WnAeH2R9EXM3PXPO7ZOYqB9HV0kazepKGQYsm52bwwbpjP_TGxIagXD= n1dmE5RZHfhJaI-7Q4nFSNg$ for graphic product... ATTN...WFO...LZK...OUN...SGF...SHV...TSA... ATTN...RFC...ABRFC...LMRFC...MBRFC...NWC... LAT...LON 37759226 37409169 36769177 35849240 34809352=20 34229509 34359606 34829616 35489567 36449463=20 37649331=20 =3D =3D =3D To unsubscribe from WX-STORM and you already have a login, go to https://lists.illinois.edu and use the "Unsubscribe" link. Otherwise email Chris Novy at cnovy@cox.net and ask to be removed from WX-STORM. --- SBBSecho 3.20-Linux * Origin: capitolcityonline.net * Telnet/SSH:2022/HTTP (1:2320/105) .