A potent upper-level system will stall all week across Alberta and Saskatchewan. The unsettled pattern will bring much-needed rainfall, thunderstorms, much below seasonal temperatures, and even accumulating S*** for Banff & Jasper.
Beneficial rainfall will persist all week in Alberta & Saskatchewan as an upper-level system stalls across the region. The heaviest rainfall is anticipated across Central Alberta where 50-75mm+ is expected by Friday. With much of that rain falling between Wednesday and Thursday. Some rainfall is in the forecast for drought-stricken High Level (Northern Alberta) & Moose Jaw (Southwestern Saskatchewan).
The much below seasonal temperatures and a soaking rainfall will make it feel more like the middle of October across the foothills. By Wednesday, temperatures will plummet nearly 10c below seasonal. Continuing through the day Thursday.
DAYS OF THUNDERSTORMS CONTINUE WITH THE THREAT OF SEVERE TUESDAY
Thunderstorms have been an almost daily occurrence over the last several days in the Prairies. The thunderstorm risk is expected to continue this week.
Monday: thunderstorms producing heavy downpours and small hail across Interior British Columbia and Northern Alberta.
Tuesday: better dynamics for potent thunderstorms across Southern Alberta (Calgary to Medicine Hat). Discrete cells or supercells could be capable of producing damaging winds and large hail.
Wednesday: daytime heating thunderstorm risk moves further East into Saskatchewan.
ACCUMULATING SNOW KICKS OFF SUMMER IN BANFF & JASPER
Between Wednesday night through Friday, accumulating up-sloping snow is expected over the high-elevation topography of Banff and Jasper National Parks. Believe or not, Friday is officially the first day of summer.