Subj : DAY3SVR: Nws Storm Prediction Center Norman Ok To : wx-storm@lists.illinois.edu From : COD Weather Processor Date : Tue Sep 17 2024 18:54:04 ACUS03 KWNS 171853 SWODY3 SPC AC 171852 Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0152 PM CDT Tue Sep 17 2024 Valid 191200Z - 201200Z ....THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS OVER PARTS OF THE UPPER MIDWEST... ....SUMMARY... Scattered severe thunderstorms are possible from mid-afternoon to early evening on Thursday across central to eastern Minnesota and north-central Iowa. ....Upper Midwest... Minor adjustments (mainly eastward expansion) to severe probabilities have been made based on latest forecast guidance for the Day 3/Thursday period, but overall forecast philosophy remains unchanged from the previous outlook. A negatively tilted upper shortwave trough will shift east/northeast from the northern Plains/Canadian Prairies toward the Upper Midwest and western Ontario. Mid/upper west/southwesterly flow will remain somewhat enhanced (around 30-40 kt 850-700 mb flow) through around 00z before the system as a whole weakens. At the surface, a cold front will extend roughly north to south/southwest from western MN into southeast NE at midday. Ahead of this feature, southerly low-level flow will maintain 60s F dewpoints across IA into eastern MN/western WI. The warm sector will remain rather narrow due to generally high pressure and a drier boundary layer over much of the Midwest east of the MS River. Nevertheless, within the axis of greater moisture/low-level theta-e, around 1000-2000 J/kg MLCAPE is forecast. Organized thunderstorm clusters and line segments will pose a risk of isolated severe gusts and hail through early evening. The severe risk should rapidly diminish beyond 00z with loss of daytime heating, limited moisture/instability with eastward extent, and weakening deep-layer flow. ...Leitman.. 09/17/2024 $$ = = = 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 3.20-Linux * Origin: capitolcityonline.net * Telnet/SSH:2022/HTTP (1:2320/105) .