ACUS02 KWNS 150523 SWODY2 SPC AC 150522 Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1222 AM CDT Sat Jun 15 2024 Valid 161200Z - 171200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS OVER PARTS OF THE NORTHERN PLAINS AND UPPER MISSISSIPPI VALLEY LATE ON SUNDAY AND SUNDAY NIGHT... ...SUMMARY... Scattered strong to severe storms are expected Sunday evening and overnight from parts of the northern Plains into the upper Mississippi Valley, with hail the primary risk. ...Synopsis... On Sunday, an upper trough will move east/northeast across MT and the far northern Plains, becoming negatively tilted as the parent low moves into MB. Meanwhile, a lead wave will move quickly east across the Great Lakes region around the north side of a strong upper ridge. Late in the period, height falls will again increase across the Pacific NW into the Rockies as another trough amplifies there. At the surface, a nearly stationary front will extend roughly from northeast CO into southern MN, with a weak lee trough from eastern CO into NM. A prominent surface ridge will extend from the high pressure center over the Mid Atlantic southwestward toward the Gulf Coast. A broad area of southwest winds around 850 mb will maintain a warm low-level air mass south of the stationary front across the Plains and around the upper ridge as warmer air spreads east across the Great Lakes. The presence of a moist and unstable air mass in the vicinity of the stationary front should be the primary focus for scattered storms, some severe, late in the day and overnight from eastern WY toward MN and WI. ...WI into MI Early...then WY to WI Late... Rain and storms are likely to be ongoing Sunday morning over WI, in a region of low-level warm advection, and where elevated instability will be substantial. This activity will progress quickly east toward Upper MI and perhaps northern Lower MI, with a general weakening trend. However, marginal hail cannot be ruled out especially early in the day. Behind this wave of activity, strong instability will develop. However, lift will be quite weak as temporary height rises occur. Still, a weak surface boundary along with peak heating could initiate isolated cells capable of hail from MN into WI during the late afternoon. More likely, most of the activity will hold off until after 00Z, as elevated instability builds back north. Between 03-06Z, scattered storms will be likely from eastern WY across parts of NE and SD, southern MN, northern WI and into western Upper MI. Vigorous convection will likely produce large hail at times, with favorable mid and high level flow elongating hodographs despite the main wave well north of the region. Elsewhere, more isolated storms will be possible extending south along the dryline from southwest NE into western KS and far eastern NM. Locally strong gusts and brief hail may occur, but shear will be weak. ..Jewell.. 06/15/2024 $$