Subj : MESO: Nws Weather Prediction Center College Park Md To : wx-storm@lists.illinois.edu From : COD Weather Processor Date : Mon Apr 29 2024 04:56:34 AWUS01 KWNH 290456 FFGMPD ILZ000-MOZ000-ARZ000-291055- Mesoscale Precipitation Discussion 0199 NWS Weather Prediction Center College Park MD 1255 AM EDT Mon Apr 29 2024 Areas affected...Portions of Central/Southern MO into Central/Southern IL Concerning...Heavy rainfall...Flash flooding possible Valid 290455Z - 291055Z SUMMARY...A broken band of showers and thunderstorms continues to advance northeastward across the middle MS Valley. Given relatively wet antecedent conditions and locally heavy rainfall rates, a few instances of flash flooding will be possible overnight. DISCUSSION...A shortwave impulse continues to advance northeastward through the middle MS Valley which is interacting with a nose of at least modest instability and shear for a broken axis of locally heavy showers and thunderstorms. The southwest flank of the vort center over central MO is currently the most convectively active region and where the heaviest rainfall rates are focused. A low-level jet of 40 kts is driving a corridor of stronger moisture convergence and this coupled with MLCAPE values of as much as 500 to 1000 J/kg are helping to yield rainfall rates occasionally of 1 to 1.5 inches/hour. A belt of 30 to 40+ kt effective bulk shear values are helping to favor a persistent degree of organization with some of the convection too despite instability being relatively modest. This shortwave energy should advance through eastern MO and gradually into central/southern IL later in the night, but there will likely be a continuation of at least broken bands of convection given the level of moisture convergence/forcing and lingering instability. The activity will also tend to be aligned in a southwest/northeast fashion with the deeper layer steering flow, and therefore there may be some cell-training that occurs. The antecedent conditions over the region are relatively wet, and with the potential for locally an additional 2 to 3 inches of rain overnight, there may be a few instances of flash flooding. Orrison ....Please see https://urldefense.com/v3/__http://www.wpc.ncep.noaa.gov__;!!= DZ3fjg!8AMi83DnDNBBkVYK-NH0bNBs2Y4DhdabzJhcxqVYB-hUu6CdIJ3kXDMYu_7POPCnEcNy= Ww2x0q77PuWn9GlbS4m8Urc$ for graphic product... ATTN...WFO...ILX...LSX...LZK...PAH...SGF... ATTN...RFC...LMRFC...MBRFC...NCRFC...OHRFC...NWC... LAT...LON 40328909 39848835 39138844 38488883 37488967=20 36689076 36399174 36439257 36879273 37929197=20 39129138 40089024=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) .