Subj : MESO: Nws Weather Prediction Center College Park Md To : wx-storm@lists.illinois.edu From : COD Weather Processor Date : Tue Mar 05 2024 21:39:16 AWUS01 KWNH 052139 FFGMPD TNZ000-KYZ000-INZ000-ILZ000-MOZ000-060335- Mesoscale Precipitation Discussion 0078 NWS Weather Prediction Center College Park MD 437 PM EST Tue Mar 05 2024 Areas affected...Portions of the Lower OH Valley Concerning...Heavy rainfall...Flash flooding possible Valid 052135Z - 060335Z SUMMARY...Some gradual increase the coverage and intensity of showers and thunderstorms can be expected going through the late afternoon and early evening hours. A localized threat for flash flooding will exist given concerns for at some cell-training. DISCUSSION...The latest GOES-East satellite imagery in conjunction with radar shows some uptick in the coverage of shower and thunderstorm activity over the last couple of hours across portions of the Lower OH Valley with the rainfall rates tending to increase as boundary layer instability increases. While still modest, MLCAPE values near and just north of the OH River have increased to as much as 500 to 1000 J/kg. Some additional destabilization is expected over the next 1 to 2 hours ahead of sunset, and this coupled with a relatively broad area surface moisture convergence focusing out ahead of a cold front should tend to favor an additional expansion of convective activity. However, with a general lack of shear, the organization of the convection should be limited. Rainfall rates are expected to increase locally to as high as 1" to 1.5"/hour with some of the stronger cells heading through the late afternoon and early evening hours, and with the convection overall becoming aligned more parallel to the mean steering flow ahead of the cold front, there will be some concerns for cell-training which will favor locally excessive rainfall totals. Some spotty 2 to 4 inch rainfall amounts will be possible and especially where any southwest to northeast oriented bands of convection can set up ahead of the cold front. This may result in some localized areas of flash flooding. Orrison ....Please see https://urldefense.com/v3/__http://www.wpc.ncep.noaa.gov__;!!= DZ3fjg!6gR8rz0fVCQLOZW3YOQZb_n6cs7UEaopdg9An1ekx-_TSfXRaqng0p4Kwu40V_N3Y64b= dTvJEl2eboyCQWXOzuhhdyQ$ for graphic product... ATTN...WFO...ILN...ILX...IND...LMK...MEG...OHX...PAH... ATTN...RFC...LMRFC...NCRFC...OHRFC...NWC... LAT...LON 39598664 39598520 38948491 37928634 36648776=20 36198845 36028903 36288956 36748958 38118874=20 38878800=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) .