Subj : DAY1SVR: Day 1 Convective Outlook To : wx-storm@lists.illinois.edu From : COD Weather Processor Date : Fri Jul 04 2025 16:32:17 ACUS01 KWNS 041632 SWODY1 SPC AC 041630 Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1130 AM CDT Fri Jul 04 2025 Valid 041630Z - 051200Z ....THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM EASTERN NORTH DAKOTA INTO NORTHERN MINNESOTA... ....SUMMARY... Scattered severe thunderstorms are possible later today into the evening over the Upper Midwest. Severe gusts will be the primary hazard. Isolated severe gusts and hail may also occur from eastern Oregon into portions of the northern Great Basin/Rockies. ....Central High Plains into the Upper MS Valley... Recent satellite imagery shows expansive upper ridging from the Lower MS Valley into western Ontario, with several disturbances along the periphery of this ridge. The shortwave trough currently moving through the central Rockies/central High Plains will be the most impactful for today's severe potential as it continues northeastward towards the very moist airmass in place across the northern/central Plains and Upper Midwest. Current surface observations reveal a large reservoir of dewpoints greater than 68 deg F across the northern/central Plains, with higher dewpoints (70+ deg F) farther northeastward across the Upper MS Valley. Strong heating is anticipated over the region, particularly the Upper Midwest, destabilizing the airmass by the early afternoon and contributing to strong to very strong buoyancy. Low-level convergence along a southeastward-progressing cold front, as well as along expected pre-frontal troughing, will augment large-scale ascent provided by the approaching shortwave. All of this lift will provide the impetus for convective initiation. Initial development appears most likely in the early afternoon (i.e. around 18Z) over northeast/eastern CO, NE Panhandle/western NE, and western KS. Vertical shear and buoyancy will be modest in this region, limiting storm strength and organization. Even so, steep low-level lapse rates and moderately high cloud bases could result in a few strong gusts. A relatively greater severe potential exists farther north over the eastern Dakotas into northern/central MN. Here, strong buoyancy (i.e. 2500-3500 J/kg of MLCAPE) is expected by the late afternoon. Vertical shear will be relatively modest, but the strong buoyancy should support robust updrafts capable of precipitation loading and water-loaded downbursts. Given the limited shear and progressive cold front, a quick transition to an outflow-dominant, linear structure is anticipated. A few stronger gusts are possible within this line as well. Isolated large hail could occur with the strongest, early-stage cellular storms. ....Eastern Oregon into the Northern Great Basin/Rockies... Extensive cloud cover has begun to clear from south to north as a lead shortwave trough progresses through the region. Secondary shortwave trough currently moving through northern CA is expected to progress eastward/northeastward into the region later this afternoon, fostering additional storm development this afternoon. Buoyancy will be modest, but moderate mid-level flow (i.e. 40-45 kt at 500 mb) will persist, supporting the potential for a few stronger/more organized updrafts. A locally greater severe wind risk may materialize across southern ID and northern UT where stronger heating and deeper mixing is anticipated. ...Mosier/Moore.. 07/04/2025 $$ = = = 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) .