Subj : DAY1SVR: Day 1 Convective Outlook To : wx-storm@lists.illinois.edu From : COD Weather Processor Date : Mon Sep 15 2025 16:33:46 ACUS01 KWNS 151633 SWODY1 SPC AC 151632 Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1132 AM CDT Mon Sep 15 2025 Valid 151630Z - 161200Z ....THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS THE NORTHERN HIGH PLAINS...NORTHERN MINNESOTA...OZARKS/MID-SOUTH...AND COASTAL NC/VA... ....SUMMARY... Isolated severe wind gusts are possible across Wyoming into western South Dakota this afternoon to early evening, as well as portions of the Ozarks/Mid-South. Isolated severe hail and damaging winds are possible across far northern Minnesota in the early to mid-afternoon. A brief tornado is possible in the northeast North Carolina vicinity in the early morning Tuesday. ....Wyoming to Black Hills vicinity... A shortwave trough over western Idaho will move east across Wyoming/western South Dakota during the day, as several embedded vorticity maxima contribute regions of enhanced ascent. Steep mid-level lapse rates of 8-9 deg C/km, combined with diurnal heating, will result in MLCAPE of a few hundred J/kg across much of the area. Despite weak buoyancy, the favorably-timed ascent will contribute to thunderstorm development/intensification this afternoon as storms approach northeast Wyoming/western South Dakota. Some hail could occur, and a deep and well-mixed boundary layer will lead to high-based convection capable of isolated strong/damaging gusts through early evening, with intensities diminishing thereafter as nocturnal cooling commences. ....Northeast North Carolina/southeast Virginia... A surface low southeast of Cape Hatteras is forecast to move towards the North Carolina coast through 12z Tuesday, with a belt of stronger low-level flow developing north/northwest of the low. Variability remains regarding the forecast location of the low and strength of low-level winds, however a conditional risk for a tornado would exist late tonight through early Tuesday morning with stronger convective elements, should sufficient low-level hodograph curvature develop as high theta-e air is advected west. ....Far northern Minnesota... Thunderstorm development is expected this afternoon within a northwest-southeast oriented arc from southeast Manitoba across northeast Ontario as a shortwave trough becomes increasingly negatively tilted while lifting northeast. Although development south of the international border is uncertain, some global guidance (and a convection-allowing model or two) suggest isolated development is possible. Moderate buoyancy and effective shear of 35-40 kt over far northern Minnesota suggest a conditional risk for severe wind/hail would exist if/where storm development occurs. ....Missouri/Mid-South.. Near and west/southwest of a residual front, a few strong/locally damaging wind gusts will be possible again this afternoon with pulse-type storms within a weakly-sheared but strongly unstable (MLCAPE of 2500-3000 J/kg) thermodynamic environment. ...Guyer/Thornton.. 09/15/2025 $$ = = = 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) .