Calgary weather: Frost possible overnight in central and southern Alberta [Video]

This week will begin with mild and clear conditions in central and southern Alberta.

In Calgary, the daytime high will reach 21 C on Monday with highs in the low 20s for much of southern Alberta.

There will be very little cloud cover and only a light wind throughout the day and overnight, and (especially) in rural communities frost is possible overnight.

Nocturnal cloud cover can serve to trap heat in during cooler overnight periods, and wind can help to mix the air in the lowest levels of the atmosphere (closest to the surface).The absence of both in transitional seasons like Spring and Fall can result in frost and/or early morning fog.

Rain is expected in the southeast corner of Alberta later on Tuesday, with the potential for some unusually intense storms for this time of year.

This precipitation is linked to a low pressure system with a southerly flow, …