Workweek Outlook: Below seasonal start to spring

The official start of spring is this Tuesday at 12:15 p.m. local time. Although the combination of sunshine and light winds this week will bring a sort of spring-like feel to the air, temperatures are expected to continue below-seasonal. High temperatures will gradually rise through the workweek but may be as much as 6 degrees Celsius below the normal early in the week.

Long-range forecast trends continue to suggest that below-seasonal temperatures will linger for the majority of the next two weeks – with some computer model guidance continuing this pattern well into April.

So, why can’t we shake this weather pattern? During the spring it is quite common to see extended periods of what is called “atmospheric blocking” over the Eastern Pacific Ocean and the Atlantic Ocean. In short, atmospheric blocking is a product of large-scale patterns in atmospheric pressure that set up in such a way as to prevent the usual west-to-east progression of weather across the continent. As a result, similar weather can be observed for several days or even weeks in areas that are affected by blocking.

The primary driver of colder risks as we head into the long-range will be a stagnant ridge of high pressure over the Eastern Pacific Ocean and into Alaska. While this will bring above-normal temperatures across even the northernmost portions of Alaska it will serve to support a trough, and thus cooler-than-normal temperatures for not only Ontario, but much of the country.

Skies will be mainly clear on Monday. High temperatures reach -2°C in the city with cooler temperatures toward Lake Superior. Winds are forecast to remain light out of the north.

Abundant sunshine persists on Tuesday. Highs climb to -2°C in the city, except cooler toward Lake Superior. Winds continue to be light and variable through the day. Cloudiness begins to develop in the evening.

A mix of sun and cloud is likely on Wednesday morning before skies become cloudy in the afternoon. Winds will be light and out of the north with high temperatures near 0°C.

Cloudiness lingers into Thursday, but gradual clearing should begin later in the afternoon. Daytime highs of 1°C are forecast.

Sunny skies close out the workweek with highs near 2°C. Some cloudiness moves in after midnight.