Subj : MESO: Nws Weather Prediction Center College Park Md To : wx-storm@lists.illinois.edu From : COD Weather Processor Date : Sat Apr 05 2025 01:34:27 AWUS01 KWNH 050133 FFGMPD TNZ000-KYZ000-INZ000-ILZ000-MOZ000-ARZ000-050725- Mesoscale Precipitation Discussion 0124 NWS Weather Prediction Center College Park MD 933 PM EDT Fri Apr 04 2025 Areas affected...northern AR across mid MS/lower OH Valleys into central IN Concerning...Heavy rainfall...Flash flooding likely Valid 050132Z - 050725Z SUMMARY...Numerous to widespread flash flood coverage is expected to affect locations from northern AR into and across the mid MS/lower OH Valleys into central IN through 07Z. An elongated axis of heavy rain with embedded training is expected to produce a broad swath of 1 to 3 inch rainfall totals with embedded maxima over 5 inches possible. DISCUSSION...Regional radar imagery at 01Z showed an axis of heavy rain that extended from the ArkLaTex into central IL/IN with a large number of ongoing flash flood warnings and reports. Within this axis were areas of training from SW to NE with MRMS-derived hourly rainfall maxima of 1 to 2 inches (locally higher) since 21Z. A surface low was analyzed over southwestern AR, with a quasi-stationary front extending northeastward into the lower OH Valley, before turning eastward along the KY/TN border. A strong 850 mb jet axis of 40 to 55 kt was present just ahead of the surface low, streaming anomalous precipitable water values of 1.5 to 1.7 inches north-northeastward from the western Gulf and ascending over the strongly defined baroclinic zone over the Mid-South. Unidirectional flow in the low to mid-levels above the LFC has, and will continue to support, areas of training overnight. Short term forecasts take the warm front northward within the highly amplified large scale flow over the lower 48 and form a surface low along the front, expected to reach east-central IL at 06Z. Strong ascent will continue ahead of the low and lifting warm front with continued areas of training containing rainfall rates of 1-2 in/hr (locally higher), supported by 500 to 1500+ J/kg MUCAPE. Aiding ascent will be the right entrance region of a strengthening anitcyclonically curved upper level jet max over the upper Great Lakes. A broad axis of heavy rain is likely to extend from central AR into IL/IN with a gradual eastward translation, ahead of the cold front and with possible eastward bowing segments of the line, allowing for locally enhanced training/high rainfall rates just south of the bowing segments. Convective orientation will often match the mean steering flow, supporting prolonged periods of training that will gradually shift off toward the east into portions of the lower OH Valley which have received very heavy rain over the past 24-48 hours. Numerous to widespread coverage of flash flooding is likely through 07Z with locally significant impacts possible across a few locations. Otto ....Please see https://urldefense.com/v3/__http://www.wpc.ncep.noaa.gov__;!!= DZ3fjg!95-tfsyPL9x22f_NUxd8Mvhnp6SCNwmNNRzpvSVyLLa4UD3Sp1vT4I23n6f91th7_DQg= UsaVaMwSz6_n83TcxsomfhU$ for graphic product... ATTN...WFO...ILN...ILX...IND...LMK...LSX...LZK...MEG...OHX... PAH...SGF... ATTN...RFC...ABRFC...LMRFC...NCRFC...OHRFC...NWC... LAT...LON 40448738 40308540 38828509 37328674 36208886=20 35029067 35219201 36079193 38378992=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) .