Subj : MESO: Nws Weather Prediction Center College Park Md To : wx-storm@lists.illinois.edu From : COD Weather Processor Date : Wed Apr 19 2023 07:27:13 AWUS01 KWNH 190727 FFGMPD WIZ000-MNZ000-IAZ000-191326- Mesoscale Precipitation Discussion 0196 NWS Weather Prediction Center College Park MD 326 AM EDT Wed Apr 19 2023 Areas affected...northern Iowa, southern Minnesota, and far western Wisconsin Concerning...Heavy rainfall...Flash flooding possible Valid 190726Z - 191326Z Summary...Localized areas of excessive runoff are possible over the next 6 hours with heavy rainfall falling on wet soils and any lingering snowpack. Discussion...Elevated convection has materialized in and upstream of the discussion area over the past few hours. Convection across Iowa and southern Minnesota has been driven by convergence rooted just above 850mb and very steep lapse rates aloft (7.5+ C/km H7-H5), resulting in areas of 1000-1500 J/kg MUCAPE. Additional convection across eastern South Dakota (just west of the MPD area) developed across higher terrain and grew upscale while traveling eastward. The heavier downpours are resulting in localized areas of 1+ inch/hr rainfall rates in north-central Iowa currently, with these rates being enhanced by somewhat slower northeastward movement of storms (20 knots) and backbuilding toward the upstream instability/mid-level lapse rates. Additional convection across far eastern Nebraska/southwestern Iowa resulted in a few areas of heavier rain rates exceeding 1 inch/hr earlier tonight as well.=20 Meanwhile, storms across eastern South Dakota are traveling eastward and should provide an additional round of precipitation across the discussion area perhaps beginning as soon as 0830Z across southwestern Minnesota. The storms are moving northeastward toward areas of wet soils from snow melt earlier today (as indicated by daytime satellite imagery). FFGs are in the 1.5 inch/hr and 1.5-2 inch/three-hour range and current convective trends indicate potential for these thresholds to be reached but only on a localized and spotty basis where any backbuilding or repeating convection can materialize. It is possible that a few spots in the discussion area could experience 2-3 rounds of precipitation this morning. 1-1.75 inch totals are possible in a few spots this morning. Marginal/isolated excessive runoff potential exists with convection in this area through 13Z. Cook ....Please see https://urldefense.com/v3/__http://www.wpc.ncep.noaa.gov__;!!= DZ3fjg!-Mm5R1njyCyq2lVGsnrd-A-s-KNlbB3mqecsYp6kOK6J3dga5M-gG_k5Or8REFbeI73F= lu4bgjvBGh35w0OtpNfhVyc$ for graphic product... ATTN...WFO...ARX...DLH...DMX...DVN...FSD...MPX... ATTN...RFC...MBRFC...NCRFC...NWC... LAT...LON 45959478 45859322 45139184 43389117 42559114=20 41849162 41709261 42729447 43709587 44769615=20 45759575=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 3.14-Linux * Origin: capitolcityonline.net * Telnet/SSH:2022/HTTP (1:2320/105) .