Severe threat moves east tomorrow

Map valid for 1pm CDT Friday afternoon

Severe thunderstorms will be/are currently impacting parts of Alberta and Saskatchewan this afternoon/evening, bringing with them hail and very strong winds. This threat will move east tomorrow and impacted parts of southeast Saskatchewan and possibly extreme southwestern Manitoba.

While instability will be generally limited, ample moisture and lift from a cold front will initiate thunderstorms somewhere in south-central Saskatchewan. These storms should then move southeast towards the SK/MB border in the afternoon and evening hours.

Energy Helicity Index depicting some weak instability at 5pm CDT

Some strong/severe storms are expected by the late afternoon/evening hours near Estevan-Carlyle-Moosomin area as ongoing storms tap into the axis of stronger instability. Although unlikely, there is a small window for rotating updraft before storm merger occurs along the warm front depicted in our risk area (first picture) although wind profiles are fairly poor for tornadogenesis.

Main threats (according to us):

• Downburst winds

• Heavy downpours

• Small hail

• Brief landspout tornado or two possible

Watches likely issued:

• Severe thunderstorm watches

The strongest cells may also remain south of the International Border, in which case heavy downpours and winds will be the main threat for areas of Saskatchewan. Watches are likely tomorrow morning or early afternoon in any case.

Official thunderstorm outlook for Friday issued by the Prairie and Arctic Storm Prediction Center as of 3pm CDT

Saskatchewan

• Area(s): Southeast and Northwest

• Timing: Friday afternoon and evening

• Threats: 2-3 cm hail, wind gusts to 100 km/h, and funnel clouds possible over northwestern Saskatchewan

A few thunderstorms are expected over southeastern Saskatchewan on Friday afternoon, with the potential for some of these storms to become severe. The main threats will be damaging winds to 100 km/h and hail to the size of loonies. Funnel clouds are possible over northwestern Saskatchewan

Manitoba

• Area(s): Far southwest

• Timing: Friday afternoon and evening

• Threats: 2-3 cm hail, wind gusts to 100 km/h

For the eastern prairies, a few thunderstorms may sneak into far southwestern Manitoba on Friday afternoon, with the potential for some of these storms to become severe. The main threats will be damaging winds to 100 km/h and hail to the size of loonies.