Subj : DAY2SVR: Nws Storm Prediction Center Norman Ok To : wx-storm@lists.illinois.edu From : COD Weather Processor Date : Wed Feb 07 2024 17:29:58 ACUS02 KWNS 071729 SWODY2 SPC AC 071728 Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1128 AM CST Wed Feb 07 2024 Valid 081200Z - 091200Z ....THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF EASTERN IOWA...SOUTHERN WISCONSIN...AND NORTHERN ILLINOIS... ....SUMMARY... Isolated strong to severe thunderstorms may occur Thursday afternoon across parts of eastern Iowa, southern Wisconsin, and northern Illinois. ....Eastern Iowa into Southern Wisconsin and Northern Illinois... A low confidence and conditional severe threat may exist Thursday afternoon across this region as a large-scale upper trough/low ejects east-northeastward across the Upper Midwest and MS Valley. A stacked cyclone will be present across the Dakotas into MN Thursday morning, with a cold front extending southward from the deep surface low across much of the Plains. As this front moves eastward through the day, modest low-level moisture will attempt to return northward ahead of it over the lower/mid MS Valley and the Upper Midwest. There is still some disparity in latest model guidance regarding both the northward extent of appreciable low-level moisture, and the quality of said moisture. Upper 40s to low 50s surface dewpoints will likely be needed to support even a low chance for organized convection, as daytime heating should remain limited due to persistent cloud cover. Steepening mid-level lapse rates and cooling temperatures aloft may also aid in the development of weak instability by late Thursday afternoon. Most high-resolution, convection-allowing model guidance (with the exception of the 12Z HRW-FV3 and RRFS) do not develop robust convection across eastern IA, southern WI, and northern IL Thursday afternoon. This may be due to limited low-level convergence ahead of the front, with generally southwesterly flow at low/mid levels strengthening with height. Still, forecast soundings from various non-convection-allowing guidance, including the NAM, RAP, and ECMWF all show some potential for organized thunderstorms given weak MLCAPE and strong low/deep-layer shear. The GFS and ECMWF in particular show a convective precipitation signal across this region as large-scale ascent associated with an embedded shortwave trough gradually overspreads the warm sector. If thunderstorms can develop, they would be capable of producing isolated hail, strong/damaging winds, and perhaps a tornado given the favorable kinematic environment forecast. Even though overall confidence remains fairly low in convective initiation, there appears to be enough signal in various model guidance to support introduction of a small Marginal Risk to account for this somewhat conditional and isolated severe threat. ...Gleason.. 02/07/2024 $$ = = = 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) .