More storms are expected to develop today in Montana and southwestern Saskatchewan. However, storms are expected to develop late in the afternoon and more through Saskatchewan overnight. A Mesoscale Convective System (MCS) is set to move through southern Saskatchewan overnight and into Manitoba (possibly). This will highly impact Saturday's storm threat for Manitoba.
Timing: Late Friday afternoon into evening and overnight
Threats: 2-3 cm hail, 100 km/h wind gusts, locally 50 mm rainfall
Scattered thunderstorms are expected to develop late in the afternoon and evening across much of eastern, central and northern Saskatchewan. The highest potential for severe thunderstorms will be over eastern Saskatchewan late in the afternoon and on Thursday night. 2-3 cm hail, 100 km/h wind gusts and locally 50 mm rainfall will be possible with these thunderstorms. Elsewhere, non-severe thunderstorms will produce pea sized hail, locally heavy downpours and gusty winds.
Timing: Friday overnight into Saturday morning
Threats: 2 cm hail, 100 km/h wind gusts and locally 50 mm rainfall
Scattered to numerous thunderstorms are expected over western Manitoba on Thursday night as a cluster of thunderstorms moves into the province from Saskatchewan. These thunderstorms will likely move into the province after midnight and have the potential to produce 2 cm hail, 100 km/h wind gusts and locally 50 mm rainfall.
Supercells with large hail and severe localized gusts are likely in the first few hours of the convective cycle, and a tornado cannot be ruled out. Upscale evolution to an MCS, with wind as the primary hazard, is expected this evening into tonight across northeastern MT and some parts of western/northern ND. A more-focused area of greater wind probabilities may be needed in a succeeding outlook once mesoscale details influencing potential MCS track/morphology become better defined. -NOAA Storm Prediction Center