Subj : MESO: Nws Weather Prediction Center College Park Md To : wx-storm@lists.illinois.edu From : COD Weather Processor Date : Tue Apr 02 2024 06:08:11 AWUS01 KWNH 020608 FFGMPD OHZ000-KYZ000-INZ000-ILZ000-MOZ000-021200- Mesoscale Precipitation Discussion 0128 NWS Weather Prediction Center College Park MD 207 AM EDT Tue Apr 02 2024 Areas affected...southern through eastern Missouri, southern/central Illinois, southern/central Indiana, portions of Kentucky, and southwestern Ohio Concerning...Heavy rainfall...Flash flooding possible Valid 020606Z - 021200Z Summary...A series of convective complexes were merging/growing upscale while producing 1+ inch/hr rain rates in spots. These trends will continue through the next 3-6 hours, posing flash flood potential across the discussion area. Discussion...A series of forward propagating, linear convective segments have began to grow upscale over the past 1-2 hours, forming a large convective complex that extends from southwestern Missouri (near Springfield) to near Saint Louis to near Terre Haute, IN. The complex was forming a relatively extensive outflow that merges with a synoptic warm front across Illinois and Indiana. Meanwhile, the pre-convective environment supporting the ongoing activity was characterized by approximately 1000 J/kg SBCAPE and strong southwesterly inflow along a 45-60 knot low-level jet axis emanating from the Ozarks. Convergence along the nose of this jet and strong low-level warm advection will likely maintain deep convection through at least 12Z this morning. The orientation of convection, however, with outflow generally parallel to west-southwesterly steering flow aloft will allow for areas of localized training and rain rates exceeding 1 inch/hr.=20 These rates were generally less than FFG thresholds (around 1.5 inch/hr), and a slow but notable rightward component of motion relative to flow aloft was allowing for heavier rainfall to move toward drier soils nearer the Ohio River.=20 The ongoing scenario should support at least a modest flash flood risk over the next few hours. Areas of convective training should continue through 12Z that could support rain rates exceeding 1.5 inches/hr at times, with low-lying and/or sensitive areas potentially experiencing excessive runoff. A lengthy duration of heavier rainfall could also result in 2 inch amounts over a three hour period that would also contribute to flash flood concerns (with 2 inch/3 hr FFG thresholds noted across the area). The leading edge of the expanding MCS should reach southwestern Ohio areas by 09Z. Cook ....Please see https://urldefense.com/v3/__http://www.wpc.ncep.noaa.gov__;!!= DZ3fjg!8cUF2pW_ZGNxYd6O3UcC7KpHJpc8LMwXNbDSxRRRaepMuv0yOA0NxCHwkECRacLMW87W= JD7Y_Ayb8VpNGVgp0lvhiIA$ for graphic product... ATTN...WFO...ILN...ILX...IND...LMK...LSX...PAH...SGF... ATTN...RFC...LMRFC...MBRFC...NCRFC...OHRFC...NWC... LAT...LON 40128421 39508371 38888386 38138510 37008853=20 36609172 36719324 37569334 38339232 39269039=20 39848844 40078547=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) .