Subj : MESO: Nws Weather Prediction Center College Park Md To : wx-storm@lists.illinois.edu From : COD Weather Processor Date : Thu Jan 30 2025 22:03:34 AWUS01 KWNH 302203 FFGMPD TNZ000-KYZ000-INZ000-ILZ000-MOZ000-ARZ000-310200- Mesoscale Precipitation Discussion 0009 NWS Weather Prediction Center College Park MD 502 PM EST Thu Jan 30 2025 Areas affected...mid-MS Valley into lower/middle OH Valley Concerning...Heavy rainfall...Flash flooding possible Valid 302200Z - 310200Z SUMMARY...Areas of moderate to heavy rain will maintain a flash flood threat from northeastern AR/southeastern MO into the lower and middle OH Valleys and much of western and central KY through at least 02Z. Hourly rainfall of 0.5 to 1.0 inches will be possible along with 3 hourly rainfall up to 2 inches. DISCUSSION...A broad area of moderate to heavy rainfall extended from near the MO Bootheel into the lower OH Valley as of 2130Z. This area of rainfall has been translating northeastward during the day and has been responsible for peak hourly rainfall up to about 1 inch from the eastern AR/MO border into western KY and northwestern TN since ~18Z. While hourly rainfall totals have not been too high given MUCAPE has largely remained below 500 J/kg, 3-hour rainfall totals of 2 to 3+ inches have resulted in numerous reports of flooding and flash flooding from southwestern to northeastern AR. The heaviest rainfall has been occurring at the nose of a 50-60 kt low level jet measured between 925-850 mb, which has been overrunning a surface warm front lifting north across AR and northern MS. The axis of greatest low level moisture transport is likely to continue to slowly shift east into KY/TN over the next few hours with an elevated convergence axis aloft focusing from near the MO Bootheel into the lower OH Valley. The orientation of this low level convergence axis will be parallel to the mean steering flow, allowing for repeating rounds of moderate to heavy rain. While instability is likely to remain limited into the late evening/early overnight hours, forcing will remain strong in the form of low level warm air advection and convergence beneath a strengthening area of upper level divergence located within the right-entrance region of a 150-160 kt upper level jet max centered over OH/PA/NY. Peak hourly rainfall of 0.5 to 1.0 inches and 3-hourly rainfall of 1-2 inches may result in additional flash flood concerns across downstream locations along the OH Valley as these rains fall on top of locations that have already picked up 2 to 3+ inches of rain since this morning. Embedded within this threat could be an isolated spot or two with higher end runoff/flooding depending on local hydrologic conditions. Otto ....Please see https://urldefense.com/v3/__http://www.wpc.ncep.noaa.gov__;!!= DZ3fjg!_WfeXhkUoEcRdU2jQCUfJEVb89Eaqg1ZGQYuJA1_DpAdmS-upWdTLbPLYGO5d1LDBdZx= HPDxtoLrEc-3uVEsyc_L5_A$ for graphic product... ATTN...WFO...ILN...ILX...IND...JKL...LMK...LSX...LZK...MEG... OHX...PAH... ATTN...RFC...LMRFC...NCRFC...OHRFC...NWC... LAT...LON 38848597 38598485 38008385 37228401 36768481=20 36528671 36118840 35438943 35109024 35369091=20 36259103 37329028 38618767=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) .