Subj : DAY1SVR: Day 1 Convective Outlook To : wx-storm@lists.illinois.edu From : COD Weather Processor Date : Sat Jul 26 2025 16:48:30 ACUS01 KWNS 261648 SWODY1 SPC AC 261646 Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1146 AM CDT Sat Jul 26 2025 Valid 261630Z - 271200Z ....THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS THE NORTHERN PLAINS AND MID-ATLANTIC... ....SUMMARY... Severe thunderstorms accompanied by damaging wind gusts are possible this afternoon through tonight in parts of the northern Plains. Isolated strong to severe storms will also be possible from the Ohio Valley and lower Great Lakes into the mid-Atlantic region, and across the central High Plains and much of Montana. ....Northern Plains... Ahead of an upper low over northern California/western Nevada, midday water vapor imagery reflects a lead shortwave trough moving northeastward over northern Utah/eastern Idaho and western Wyoming. In this regime, forcing for ascent and gradual cooling aloft will occur through late today over northern Wyoming and southern/eastern Montana. Northerly/upslope surface winds, combined with strong heating and moderate CAPE values, will promote the development of scattered high-based gusty thunderstorms by late afternoon. This will initially occur across southern Montana and toward the Big Horns/northeast Wyoming. Additional high-based storm development is expected near the surface low and southward-extending surface trough into the central High Plains. Storms that move into the western Dakotas will encounter progressively higher CAPE and likely grow upscale through the evening with a greater risk of organized severe winds, aside from some continued hail potential. As least some late-night severe risk will probably persist across North Dakota/eastern South Dakota into Minnesota. ....Midwest to Mid-Atlantic States/Delmarva... Multiple clusters of have persisted and/or reinvigorated early today in a corridor spanning north-central Illinois/northern Indiana, as well as central Pennsylvania. Moist/humid conditions will exist south of the convectively reinforced boundary and away from areas of persistent cloud debris (such as northward into Lower Michigan), with a reservoir of ample buoyancy contributing to a diurnal intensification of storms as multiple convectively enhanced mid-level disturbances interface with the effective front and nearby warm sector. The strongest storms will be capable of damaging winds, and a somewhat more favorable corridor for severe thunderstorms/wind damage appears to exist across the Mid-Atlantic States including south/southeast parts of Pennsylvania toward the Delmarva/Chesapeake Bay. ...Guyer/Thornton.. 07/26/2025 $$ = = = 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 3.28-Linux * Origin: capitolcityonline.net * Telnet/SSH:2022/HTTP (1:2320/105) .