Warnings issued west of Calgary due to rapidly-changing conditions

Weather warnings issued by Environment and Climate Change Canada for Alberta and B.C. on Feb. 29, 2024, include snowfall warnings (white), rainfall warnings (green) and winter storm warnings (blue).

Much of southern Alberta woke up to warm temperatures Thursday, with many locations reporting overnight temperatures that exceeded average daytime highs for the region.

Temperatures are expected to continue to climb in the early part of the day Thursday before a rapid shift in weather patterns introduces a strong and cold north wind.

This frontal system is expected to translate to a sharp drop in temperatures over a short period of time in the late afternoon. The atmospheric temperature profile is also likely to change quite quickly which is potentially the most concerning part of Wednesday’s forecast.

An inverted trough combined with the collision of air masses means there is a high likelihood for freezing rain to develop across portions of the southwestern Prairies.

Even if the incoming precipitation remains liquid as it falls and lands on surfaces, the strong north wind of 40 to 60 km/h will increase the risk of surfaces freezing.

Given the ample supply of Pacific moisture, snow will eventually fall across southern Alberta and southern British Columbia, and given the right circumstances, will sit overtop of a layer of ice making traction especially difficult.

As of 7:30 a.m. Thursday, highways along the Alberta-BC corridor were showing accumulation on Drive BC cameras, with another five to 10 centimetres forecast for the mountain parks. Strong winds will continue to create visibility challenges due to blowing snow and icy surfaces along higher elevation and open roadways over the next 24 hours.

Environment and Climate Change Canada (ECCC) issued snowfall warnings, rainfall warnings and winter storm warnings for the mountain passes and foothills including Kananaskis and Canmore.

As of 8:30 a.m. Thursday those warnings were still in place but did not extend as far west as Calgary. Heavy snowfall and the potential for freezing rain could prompt additional warnings east of the foothills over the next 24 hours as the moisture tracks east.

Temperature-wise, Calgary will end up trapped under the sinking polar vortex until at least the middle of next week, starting with another big swing in temperatures from Thursday to Friday.

For the latest weather warnings from ECCC click here. Updated road conditions from 511 Alberta can be found here. And click here for highway conditions from Drive BC.