Rapidly changing conditions overnight in Alberta with a 20-degree drop in daytime highs mid-week

Winter storm watch east of Calgary. Jodi Hughes has a look at the five-day forecast from the Sky Watch Weather Centre.

The start of this week will be much different than the end, with daytime highs around 4 C on Monday and -19 C by Friday.

There are a number of weather warnings and advisories issued for the west, including a yellow-level snowfall warning in the foothills and portions of the B.C. interior, as well as northern Alberta and B.C.

Areas including Banff National Park and Kananaskis are expecting up to 15 centimetres of snow overnight.

Yellow-level wind warnings have been issued for the southwest corner of the Alberta with west winds up to 100 km/h possible tonight.

A frontal system will track north to south across the province late Monday and early Tuesday and as that cold front encounters some of the moisture from the Pacific low, where visibility could become compromised.

Surfaces that have experienced melting during the day and/or received any fresh rain/snow will likely see moisture freeze quickly when it encounters that intense colder air, so Environment and Climate Change Canada (ECCC) also issued a yellow-level winter storm watch for areas east of Highway 2 and the QEII.

It noted, “Icy surfaces may form quickly and be difficult to detect. High-sided vehicles may be blown around by the wind. In flurries, visibility may be quickly and suddenly reduced to near zero.”

As this system tracks east it will become an “Alberta clipper,” creating hazardous weather conditions including strong winds, a rapid drop in temperatures and poor visibility.

As such, a special weather statement was issued from ECCC for a good portion of central and southern Saskatchewan.

Calgary will start the week just outside of most of this action, with daytime highs above freezing and lows that are mild.

Winds will not be as intense as communities south of the city, but will be noticeable at 15 to 20 km/h out of the southwest.

The city should also avoid precipitation until Wednesday night as the bulk of moisture will likely get squeezed out closer to the Rockies.

Roads, sidewalks and parking lots could be slick though early Tuesday if the northern frontal system tracks as far south as the Calgary area, since there will be melting during the day on Monday.

Wednesday will be a day of transition with a rapid drop in temperatures during the day, and the high of 2 C will quickly drop 20 degrees and stay there for a couple of days.

A low-riding jet will settle over most of the country and produce a persistently cold pattern with highs in Calgary that are much colder than the average low and wind chill values by the end of the week that are close to -30.