Subj : DAY1SVR: Day 1 Convective To : All From : Mike Powell Date : Mon Sep 15 2025 09:45:29 ACUS01 KWNS 151244 SWODY1 SPC AC 151242 Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0742 AM CDT Mon Sep 15 2025 Valid 151300Z - 161200Z ....THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FROM WYOMING INTO WESTERN SOUTH DAKOTA...OVER FAR NORTHERN MINNESOTA...AND NORTHEAST NORTH CAROLINA... ....SUMMARY... Isolated severe gusts are possible across Wyoming into western South Dakota this afternoon to early evening. Isolated severe hail and damaging wind 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. ....WY to western SD... A shortwave trough over western ID will move east across WY/western SD 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 WY/western SD. 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 NC/southeast VA vicinity... A surface low southeast of Cape Hatteras is forecast to move towards the NC 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 early Tuesday morning with stronger convective elements, should sufficient low-level hodograph curvature develop, as high theta-e air is advected west across the northeast NC/southeast VA vicinity. ....Far northern MN... 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 CAM guidance suggest isolated development is possible. Moderate buoyancy and effective shear of 35-40 kts over far northern MN suggests a conditional risk for severe wind/hail would exist should storm development occur in this area. ....MO/AR vicinity... A few strong gusts will be possible again today with pulse-type storms within a weakly-sheared but strongly unstable (MLCAPE of 2500-3000 J/kg) environment. ...Bunting/Broyles.. 09/15/2025 $$ --- SBBSecho 3.28-Linux * Origin: capitolcityonline.net * Telnet/SSH:2022/HTTP (618:250/1) .