Subj : DAY3SVR: Nws Storm Prediction Center Norman Ok To : wx-storm@lists.illinois.edu From : COD Weather Processor Date : Fri Jul 12 2024 07:35:53 ACUS03 KWNS 120735 SWODY3 SPC AC 120734 Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0234 AM CDT Fri Jul 12 2024 Valid 141200Z - 151200Z ....THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM THE NORTHERN PLAINS INTO THE UPPER MIDWEST... ....SUMMARY... Strong to severe thunderstorms are possible from the northern Plains into the Upper Midwest on Sunday. ....Synopsis... Upper ridging is forecast be over the Four Corners early Sunday morning, with a belt of westerly flow aloft to its north extending across the northern tier of the CONUS (i.e. from the Pacific Northwest through the Upper Midwest and Upper Great Lakes into the Northeast). The upper ridging is expected to remain in place while a series of low-amplitude shortwave troughs move quickly through the belt of westerly flow aloft. Subtropical ridging will continue to influence the sensible weather across the Southeast. Predictability issues limit the confidence in the surface pattern across the northern Plains and Upper Midwest early Sunday morning, largely due to the influence of antecedent thunderstorms. Isolated thunderstorms, a few of which could be strong, may be ongoing across the Upper Great Lakes region early Sunday morning. An outflow boundary associated with these storms may exist somewhere across the Upper Midwest. Given the lack of a well-defined shortwave trough throughout much of the period, low-level convergence and strong buoyancy along this boundary will likely provide the impetus for afternoon/evening thunderstorm development. Vertical shear will be strong enough for a few organized storm structures, but a largely outflow-dominant storm character is anticipated, with some potential for the development of a forward-propagating convective line. Damaging gusts are the primary threat with these afternoon/evening storms. A more amplified shortwave trough is expected to progress from the southern Canadian Prairie provinces into the northern Plains late Sunday night/early Monday morning. Ascent attendant to this system is expected to lead to elevated thunderstorm development. Buoyancy and shear will be strong enough for organized storms capable of large hail and/or damaging gusts with any storms that do develop. Guidance varies slightly on the most likely location for these storms, largely due to variability in shortwave speed, but the most likely location appears to be from central North Dakota into northwest Minnesota. ...Mosier.. 07/12/2024 $$ = = = 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) .