Cold, snow, fog and freezing rain ahead of a warmup on the weekend

An infusion of cold Arctic air is continuing to be a main weather driver across Alberta, B.C. and Saskatchewan.

A low-riding jet stream sitting south of the Canadian border collided with a moisture-laden Pacific air mass and produced snow as far south as the U.S. Midwest early Tuesday. It prompted a number of weather advisories from Environment and Climate Change Canada.

Rainfall warnings (green), snowfall warnings (white), special weather statements (pink), winter storm warnings (dark blue), wind warnings (purple), and extreme cold warnings (light blue), issued from Environment and Climate Change Canada on Dec. 17, 2024.

The national weather agency warns as much as 50 to 70 millimetres of rain is possible along the West Coast starting Tuesday night.

As this frontal system tracks east and encounter cooler air, heavy wet snow is expected across the B.C. interior and extending northeast to the Alberta side of the northern edge of the Rocky Mountains.

Widespread special weather statements blanket a large portion of the B.C. interior.

Winter storm warnings have been issued for the southeast corner of British Columbia (and portions of Highway 3) with rapidly accumulating snow (up to 30 to 40 centimetres possible), poor visibility and blowing snow likely to amplify the negative effects of that incoming system.

Foggy conditions prompted a fog advisory for the Calgary region early Tuesday and light snow fell across the region.

Daytime highs are expected to peak around -14 C in Calgary on Tuesday, or 13 degrees colder than average.

Temperatures and windchill values in northwestern Alberta and the territories reached extreme cold warning thresholds.

As that same system exits B.C. and moves along the southern Alberta border on Wednesday, freezing rain is possible in the southeast corner of the province (including Medicine Hat), which could create some treacherous driving conditions – especially with snow likely to move in behind it.

The good news is an improvement is expected for the weekend.

Both daytime highs and overnight lows will be at or above freezing by Saturday, and mild conditions should persist until early next week.