Subj : DAY3SVR: Nws Storm Prediction Center Norman Ok To : wx-storm@lists.illinois.edu From : COD Weather Processor Date : Thu Jun 19 2025 07:32:08 ACUS03 KWNS 190731 SWODY3 SPC AC 190730 Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0230 AM CDT Thu Jun 19 2025 Valid 211200Z - 221200Z ....THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FROM THE NORTHERN PLAINS INTO THE UPPER MIDWEST AND GREAT LAKES... ....SUMMARY... Strong to locally severe storms are possible Saturday from the northern Great Plains into the Upper Midwest and Great Lakes. ....Synopsis... The large-scale pattern on Saturday will not change appreciably, with a seasonably deep upper trough over the West, and an amplified upper ridge over the Southeast and Ohio Valley. A lee trough and surface low will remain in place over the central/northern High Plains, with an expansive area of rich low-level moisture east of the low/trough across the Plains and upper Midwest. ....Upper Midwest/Great Lakes... Confidence is quite low regarding the details of severe-storm potential on Saturday, though conditional potential remains evident along the periphery of the upper ridge. An MCS that may develop late on D2/Friday may be moving across parts of the northern Great Lakes at the start of the period (and possibly posing a severe-wind threat), though it is possible that the bulk of this MCS will be in Ontario through the day. This MCS (or its remnant MCV) may move southeastward toward the lower Great Lakes and NY/PA by evening, and could pose some severe threat if it does not become displaced from the buoyancy reservoir to its southwest. Some redevelopment cannot be ruled out in the wake of the potential morning MCS into the upper Great Lakes/Midwest. Buoyancy and shear will remain favorable for organized severe storms, but confidence is low regarding coverage and location at this time. ....Northern Plains... Strong storms that develop on D2/Friday be ongoing Saturday morning across eastern MT, and could pose an isolated severe hail/wind threat. Guidance varies regarding instability/moisture across eastern MT later in the day, but if some diurnal destabilization can occur, then ascent related to the western trough may aid in additional strong storm development. Stronger instability will reside across the Dakotas, and the greatest relative threat for a couple supercells and/or an organized storm cluster currently appears to be across parts of ND during the afternoon and evening. However, confidence is too low for higher probabilities at this time. ...Dean.. 06/19/2025 $$ = = = 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) .