Subj : DAY3SVR: Nws Storm Prediction Center Norman Ok To : wx-storm@lists.illinois.edu From : COD Weather Processor Date : Wed Jul 26 2023 07:33:25 ACUS03 KWNS 260733 SWODY3 SPC AC 260732 Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0232 AM CDT Wed Jul 26 2023 Valid 281200Z - 291200Z ....THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FOR PORTIONS OF THE MIDWEST... ....SUMMARY... Widely scattered severe thunderstorms are possible on Thursday and Thursday night across a large portion of the Midwest. ....Synopsis... A flattened mid-level anticyclone will continue to be centered over southern states. A belt of moderately strong westerlies will extend from the northwestern CONUS eastward across the north-central U.S. and into the Northeast. A mid-level shortwave trough and associated speed max will quickly move from near Lake Superior east to the St. Lawrence Seaway. West-northwesterly mid-level flow will encompass the area from the Great Lakes west to the Dakotas east of a ridge over MT/WY. ....Great Lakes across the Midwest and Black Hills... A residual west-east frontal zone will be draped from near the Black Hills to the central Great Lakes in wake of a departing mid-level disturbance moving east over southeast Canada. A cluster of showers/storms may be ongoing Friday morning near a nose of a central U.S. LLJ near the IA vicinity. A very moist, capped, and destabilizing airmass will be located south of the frontal zone where 70s dewpoints will be common. Considerable variability is evident in model guidance as to the focusing mechanism for thunderstorm development on Friday within a weakly forced regime. Nonetheless, a reservoir of 2000-4000 J/kg MLCAPE will develop from the Dakotas into the southern Great Lakes during the day. An increase in a west-southwesterly LLJ during the evening into the overnight across the southwest Great Lakes may aid in either storm development, sustenance, or both. Have opted to include a categorical Slight Risk where confidence is highest for a cluster of thunderstorms to develop and move east-southeast. Some of this activity may reach the Lower Great Lakes late Friday night into early Saturday morning. ....Northern Rockies... Isolated to widely scattered diurnal thunderstorms are possible Friday in association with a weak mid-level disturbance forecast to move from CA/NV into the northern Rockies. Steep low- to mid-level lapse rates and sufficient mid-level flow will aid in some storm organization. Isolated severe gusts and perhaps marginally severe hail are possible with the stronger storms. ...Smith.. 07/26/2023 $$ = = = 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 3.14-Linux * Origin: capitolcityonline.net * Telnet/SSH:2022/HTTP (1:2320/105) .