Calgary weather: Mid-week cooldown with overnight temperatures around freezing [Video]

The next two days will be cooler for much of the Prairies, including Alberta.

Both daytime highs and overnight lows will be slightly below seasonal for most of southern Alberta, with early morning temperatures at or below freezing in many communities.

The main weather-maker for most of the country is a potent low pressure system parked over Hudson Bay.

That low is drawing cooling air from the north and filtering it back toward the west coast. In the southeastern Pacific a high pressure system is reinforcing a zonal pattern (creating a west to east flow along the southern borders of B.C., Alberta, Saskatchewan, Manitoba and Ontario).

Later Thursday, that ridge will start to track northeast and should disrupt that pattern while introducing warmer temperatures by the weekend.

With less than 12 hours between sunrise and sunset right now any amplified temperatures during the day will be reset overnight due to …