Cool and wet weather for the long weekend

Wednesday will be the warmest day for at least a week. Daytime highs for the May long weekend will be underwhelming and scattered showers and thunderstorms are likely every day until at least Sunday

Instability throughout central and southern Alberta Wednesday will produce showers and non-severe thunderstorms that will continue overnight.

Rain will be more persistent on Thursday and Friday but it will also impact portions of northern Alberta, which should will prove helpful than not.

The fire risk is still a major concern for areas currently dealing with wildfires, including near Grande Prairie and Fort McMurray – where both of Alberta’s wildfires that are rated as “out of control” are burning.

But, at this point, rain would need to be soaking and intense before it could dramatically alter the situation.

As of 7:30 a.m. Wednesday, air quality advisories remain in effect for northern B.C., Alberta, Saskatchewan and Manitoba with zonal flow pulling that smoke from west to east.

There will be a push from the north later Wednesday bringing stronger winds and colder air to central and southern Alberta, but this will be accompanied by rain, so air quality is unlikely to deteriorate significantly as the rain will pull any incoming particulate to the surface.

Overnight lows will be close to freezing in many communities over the weekend and mixed precipitation is possible overnight west of Calgary in higher elevations.

Within the city the urban heat island effect should keep temperatures just above freezing in most communities, but with fresh moisture in the ground this line will be close. Evaporation typically occurs in the early mornings just before sunrise – and with evaporation being a cooling process – some communities may dip below 0 C.

Monday will likely be the warmest day of the long weekend – with more sunshine expected and a forecast high of 13 C.