Calgary weather: Extreme cold warnings expand; snowfall warnings remain [Video]

A persistent weather pattern is funnelling arctic air across the Prairies, which forced Environment and Climate Change Canada (ECCC) to issue extreme cold warnings late Thursday.

The national weather agency expanded those warnings Friday night, and as of 7:30 p.m., including the Yukon, Northwest Territories, Alberta, Saskatchewan, Manitoba and Ontario.

Wind chill values under the warned areas are likely to drop to at least -40 at times, especially early in the morning Saturday.

At the same time that colder air is meandering south, a slow-moving, moisture-laden system is edging north into southern British Columbia.

That Pacific air mass is going to track east toward the southern Rockies, where it will meet up with the western edge of the polar air mass and deliver up to 15 centimetres of snow for the southwest corridor of Alberta.

Snowfall warnings issued from ECCC note visibility is likely to be compromised in this area …