Subj : DAY1SVR: Day 1 Convective To : All From : Mike Powell Date : Fri Aug 22 2025 10:01:17 ACUS01 KWNS 221251 SWODY1 SPC AC 221250 Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0750 AM CDT Fri Aug 22 2025 Valid 221300Z - 231200Z ....THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS THE CENTRAL HIGH PLAINS TO THE UPPER MIDWEST AS WELL AS ARIZONA... ....SUMMARY... Strong to locally severe thunderstorms are possible from parts of the central and northern High Plains to the Upper Midwest, and across parts of Arizona. ....Upper Midwest/Upper Great Lakes... Upper trough amplification will continue to occur over Manitoba/northern Ontario through tonight, with consequential height falls over the upper Great Lakes. A cold front will continue to advance southeastward regionally, with a semi-moist air mass preceding it. A consequential factor for portions of the region will be an MCS centered across far eastern South Dakota early this morning, which will continue to disturb the frontal zone and nearby warm sector for the first part of the day. This may especially be the case across southern Minnesota and vicinity. But on the periphery of the MCS-influenced corridor, potential severe storm development could occur by late afternoon, perhaps most likely across eastern Nebraska and western Iowa, but also across northwest Wisconsin/Upper Michigan where vertical shear will be stronger but with more modest buoyancy. Hail and damaging winds would be possible in both scenarios, but likely on a relatively isolated basis. ....Wyoming/Colorado and central High Plains... A subtle ridge-peripheral disturbance noted in water vapor imagery, along with strong surface heating, should aid thunderstorm development initially across Wyoming/Colorado. This activity should propagate east-southeast toward lower elevations in the presence of moist low-level upslope flow. Hail and wind are possible with this activity, especially within a corridor across interior/southeast Wyoming into northeast/east-central Colorado. ....Arizona... The upper high will shift west-northwestward through tonight, maintaining and potentially strengthening easterly mid-level winds across southern Arizona, in addition to the possibility of slightly cooler (degree or two C) mid-level temperatures. Lingering morning cloud cover should gradually abate into the afternoon, with a very hot/residually moist boundary layer contributing to widely scattered thunderstorm development, initially over higher terrain. West/southwestward spreading storms will pose the potential for strong wind gusts/blowing dust onto the desert floor. ...Guyer/Kerr.. 08/22/2025 $$ --- SBBSecho 3.28-Linux * Origin: capitolcityonline.net * Telnet/SSH:2022/HTTP (618:250/1) .