Subj : DAY3SVR: Nws Storm Prediction Center Norman Ok To : wx-storm@lists.illinois.edu From : COD Weather Processor Date : Mon Aug 26 2024 07:44:32 ACUS03 KWNS 260744 SWODY3 SPC AC 260743 Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0243 AM CDT Mon Aug 26 2024 Valid 281200Z - 291200Z ....THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM LOWER MICHIGAN EASTWARD TO SOUTHERN NEW ENGLAND...AND ACROSS PORTIONS OF THE DAKOTAS... ....SUMMARY... Severe storms are expected across portions of the Midwest and Northeast/Mid-Atlantic area, and over portions of the northern Plains. ....Synopsis... Upper troughing is forecast to shift into the Northeast Wednesday, as a short-wave trough cresting the central and eastern U.S. ridge moves across the Great Lakes region and southeastern Canada -- partially merging with a more substantial trough crossing Quebec and moving into the Canadian Maritimes. Upstream, a strong upper low is forecast to move eastward across the Canadian Prairie and adjacent northern Intermountain Region through the period. At the surface, a west-to-east quasi-stationary front is forecast to extend from southern New England across the Midwest, while retreating northward as a warm front across the central and into the northern Plains. This retreat will occur as a cold front shifts into the northern Plains and western Nebraska during the afternoon and evening. By the end of the period, this cold front should extend from the eastern Dakotas to the central High Plains. ....Midwest to southern New England, and south across the central Appalachians and into the Mid-Atlantic... Uncertainty with evolution of convection persists across the region at this time, as substantial model differences exist with respect to early-day/ongoing convection, as well as timing/position of synoptic features -- both surface and aloft. While the risk areas will likely require adjustment in subsequent outlooks, current indications are that storms should reintensify/develop during the afternoon as the airmass near and south of a west-to-east surface baroclinic zone becomes moderately unstable. The most favorable kinematic environment is expected to extend from lower Michigan to southern New England, but greater instability is expected westward across the Upper Ohio Valley and Midwest. As such, damaging winds would likely be the primary threat over northern and eastern portions of the region, with large hail potentially more prevalent into the Midwest. Storms -- and at least some severe risk -- will likely continue well into the evening and possibly into the overnight hours, spreading southeastward through the end of the period. ....Northern Plains... As the upper low advances eastward across the Canadian Prairie and northern Intermountain Region during the day, northward return of the surface baroclinic zone and associated moist low-level airmass into the Dakotas is expected to occur. Afternoon heating will support moderate destabilization, with storms expected to develop by late afternoon near the retreating baroclinic zone, and a cold front shifting across the northern High Plains into the Dakotas. While some risk for damaging winds may evolve, the main risk will likely be large hail -- particularly with elevated storms across North Dakota during the evening, and spreading into Minnesota overnight. ...Goss.. 08/26/2024 $$ = = = 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) .