Monday's high of -8 C, the warmest temp until Thursday

Cooler air has started to sink south across Alberta and Saskatchewan, impacting communities beyond the U.S. border.

Daytime highs are expected to sit well-below seasonal values in many communities – including Calgary, where Monday’s daytime high of -8 C will be the warmest temperature until Thursday.

Dense fog covered southern Alberta early Monday, prompting an advisory from Environment and Climate Change Canada. Fog was visible on many 511 Alberta cameras including along Highway 2 S., Highway 9 E., Highway 3 and along the QEII Highway.

Much of the fog in the southwest corner of Alberta is likely to persist late into the day until snow moves in and helps to mix it out.

Snow will track through southern British Columbia starting on Monday and peak on Tuesday and Wednesday.

Some of that snow will force it’s way into Alberta, and warnings may need to be issued as colder air and Pacific moisture combine to create heavy accumulations.

Calgary could see light flurries on Monday, with a greater likelihood later Tuesday and on Wednesday.

A strong ridge of high pressure is expected to move across B.C. by the end of the week, extending beyond the northern border.

Under that ridge warmer air will drive temperatures back above normal values for the weekend.