Extreme cold warnings will start to lift today as warmer air moves in

Freezing temperatures turning around in Calgary. Jodi Hughes has a look at the five-day forecast from the Sky Watch Weather Centre.

Windchill values across southeastern Alberta early Monday were close to -40, which was still warmer than the conditions in southern Saskatchewan.

As of 7:30 a.m. Monday, windchill values in Saskatoon and Regina were closer to -50.

A persistent weather pattern has allowed polar air to funnel across most of North America, prompting widespread cold weather warnings in both Canada and the United States.

The thresholds for issuing extreme cold warnings in Canada are highly variable and include considerations like latitude, humidity, seasonal temperature norms, etc.

In Alberta and southern Saskatchewan, extreme cold warnings are issued by Environment and Climate Change Canada (ECCC) when either the ambient temperature and/or the perceived temperature (aka windchill value) reaches at least -40 C for at least two consecutive hours.

In their warnings for southern Alberta Monday, ECCC advised “frostbite can develop within minutes on exposed skin, especially with wind chill.”

Specifically, windchill values of -40 are associated with frostbite potentially occurring within 10 minutes of exposure or less, and ECCC notes prolonged exposure to cold “creates an elevated risk to health” including hypothermia.

This current weather pattern will break down Monday as a Pacific ridge edges into B.C. and the associated warm front starts to track from west to east.

Strong winds are expected along the leading edge of the front, prompting ECCC to issue a wind warning north of the Rocky Mountains, and in B.C..

Westerly winds will intensify throughout the day along the southern edge of the mountain range too, pushing wind gusts up to 40 km/h in Calgary by the afternoon.

Extreme cold warnings should start to lift late in the morning on Monday in Alberta, but will likely persist across most of Saskatchewan and Manitoba.

Temperatures will gradually warm up throughout the day on Monday in southern Alberta, with the daily maximum likely to hit closer to midnight as opposed to the normal peak in mid-afternoon.

Daytime highs in Calgary will hover around the freezing mark for the next five days, with lows between -6 C and -8 C.

The normal range in Calgary this time of year is -3 C and -15 C.