Subj : DAY3SVR: Nws Storm Prediction Center Norman Ok To : wx-storm@lists.illinois.edu From : COD Weather Processor Date : Sun Aug 25 2024 07:28:51 ACUS03 KWNS 250728 SWODY3 SPC AC 250727 Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0227 AM CDT Sun Aug 25 2024 Valid 271200Z - 281200Z ....THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS MUCH OF THE GREAT LAKES REGION... ....SUMMARY... Severe-weather potential is evident across the Great Lakes region on Tuesday. ....Synopsis... While upper ridging/weak flow aloft prevails across most of the southern 2/3 of the country, an active northern stream will persist Tuesday. Within this stream, and upper trough will continue moving eastward across western Canada and the northwest CONUS. Meanwhile, a weaker/lower amplitude downstream trough will nonetheless be the more substantial feature with respect to convective/severe potential. This trough, initially over the north-central U.S., is forecast to shift eastward across the Upper Great Lakes and southern Ontario through Wednesday morning. At the surface, low pressure initially near the Upper Mississippi Valley will accompany the eastward advance of the upper system, moving eastward across the Great Lakes region through the period. ....Great Lakes region... Thunderstorms -- and accompanying risk for large hail and damaging winds -- are expected to be ongoing across parts of the Upper Mississippi Valley/western Upper Great Lakes region at the start of the period, in advance of the eastward-moving upper disturbance. Questions regarding initial location, and speed of advance, of this convection cast substantial uncertainties with respect to evolution of the severe threat into Tuesday afternoon and beyond. Still, as the upper system and associated surface low track eastward across the Great Lakes, and a moist boundary layer heats/strongly destabilizes through the afternoon in areas away from ongoing convection/clouds, severe threat should persist/shift eastward with time. With a belt of moderately strong deep-layer westerlies shifting across the Great Lakes in tandem with the upper system, potential for organized, rather fast-moving storms is indicated. While capping may limit convective coverage with southward extent, Wisconsin and Michigan appear likely to be the centroid of the risk. As storms spread eastward through the evening and into the overnight hours, the eastern extent of the risk is difficult to delineate at this time. At least some risk may reach as far east as the Lake Ontario/Finger Lakes region of New York and adjacent north-central Pennsylvania. ...Goss.. 08/25/2024 $$ = = = 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) .