Subj : MESO: Nws Weather Prediction Center College Park Md To : wx-storm@lists.illinois.edu From : COD Weather Processor Date : Fri Jun 06 2025 15:22:18 AWUS01 KWNH 061522 FFGMPD OHZ000-TNZ000-KYZ000-INZ000-ILZ000-MOZ000-ARZ000-062120- Mesoscale Precipitation Discussion 0380 NWS Weather Prediction Center College Park MD 1121 AM EDT Fri Jun 06 2025 Areas affected...Portions of the Middle MS and Lower OH Valleys Concerning...Heavy rainfall...Flash flooding likely Valid 061520Z - 062120Z SUMMARY...Areas of heavy showers and thunderstorms are expected to generally persist and expand in coverage going through the mid-afternoon hours from south-central to southeast MO into southern IL, along with adjacent areas of far southern IN, much of KY, and far northern TN. Heavy rainfall rates of up to 2 inches/hour and concerns for cell-training will likely result in at least scattered areas of flash flooding. DISCUSSION...The late-morning GOES-E Airmass RGB satellite imagery in conjunction with radar shows a strong MCV advancing through southwest MO in association with a long-lived MCS that is advancing well off to the east across areas of the southern Plains and lower to mid-MS Valley region. This MCV though is also associated with an area of surface low pressure along a quasi-stationary frontal zone draped west to east across southern MO and into adjacent downstream areas of the OH Valley. A separate wave of low pressure is also noted over southeast MO. The airmass pooling along this front over the lower OH Valley ahead of these waves of low pressure and the mid-level energy aloft is rapidly destabilizing with strong solar insolation and surface heating. Already there are MLCAPE values of 1500 to 2500+ J/kg pooled across much of the Mid-South with a nose of this advancing up into western and central KY. Over the next several hours, some increase in a southwest low-level jet (reaching 30+ kts) is expected across southeast MO through at least far southern IL and into western KY as the upstream MCV and related wave activity arrives. This will set the stage for stronger low-level moisture convergence and forcing along the front for a more organized and concentrated threat of heavy rainfall. However, downstream areas of far southern IN, much of KY, and far northern TN will also have a likelihood for scattered clusters of convection as favorable upper-level jet support near the front along with the boundary layer destabilization works to promote convective development. The airmass is quite moist with PWs running around 1.5 standard deviations above normal, and the increase in instability with some moderately strong effective bulk shear values of 30 to 40 kts should favor enhanced rainfall rates of up to 2 inches/hour. The latest 12Z HREF guidance and recent RRFS solutions show rather strong support for 2 to 4 inch rainfall totals with locally higher amounts possible where areas of cell-training take place. Expect a likelihood for scattered areas of flash flooding to occur going through the mid-afternoon hours, and this will be aided by locally moist antecedent conditions. Orrison ....Please see https://urldefense.com/v3/__http://www.wpc.ncep.noaa.gov__;!!= DZ3fjg!8j-4NfWH1TEZK8GT-5S97TyhZIvz-fPospdI50ntTdDNXoeQ2dzGWu2zAd-IRbIo0dnx= LLlhbM2pc-6l_YiNRJIMAy0$ for graphic product... ATTN...WFO...ILN...ILX...IND...JKL...LMK...LSX...LZK...MEG... MRX...OHX...PAH...RLX...SGF... ATTN...RFC...KRF...MSR...ORN...TIR...TUA...NWC... LAT...LON 38938567 38738312 37508282 36568430 36168812=20 36229032 36499232 37009369 37649390 38049320=20 38399116 38678906=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) .