Expect icy conditions with an enhanced freeze-thaw cycle this week

A strong ridge of high pressure setting up along the B.C. coastline will become the main weather-maker for the west – including in southern Alberta.

In a classic adiabatic pattern, snow will fall on the B.C. side of the Rockies on Wednesday leaving dry air to descend along the leeward side – the Alberta side – of the mountains.

As that dry air flows toward the foothills, it will gain in temperature faster than it lost in temperature on its ascent on the windward side of the range.

The result will be a persistent westerly pattern with elevated temperatures and enhanced evaporation – or snow melt across southern Alberta.

Daytime highs are expected to remain above freezing in Calgary starting Tuesday, and overnight lows will be warmer than the average daytime highs at times.

Since January is typically one of the coldest months across the region, any precipitation that does fall is usually in the form of snow, but with a warmer atmospheric temperature profile this week, rain or mixed precipitation is possible in the southeast corner of Alberta and central Saskatchewan Wednesday morning.

Melting will be enhanced across most of the region during the days this week, and cooler overnight temperatures will cause that melted snow to freeze on sidewalks, parking lots, and stairs.

This temperature swing might also create issues with water mains and plumbing, as daytime highs are expected to be as warm as 5 C in Calgary by Wednesday.