Spring 2021 outlook

A slowly weakening La Nina is still expected to influence the weather pattern across Canada into the spring.

The active storm track is likely to persist into British Columbia through April, leading to bouts of heavy coastal rain and a prolonged snow season in the Coastal Range and into the Rockies. Thus, we expect an extended spring ski season in the west.

The result of this expected weather pattern, above-normal snowpack and river levels may lead to a higher-than-usual threat of spring flooding and ice jams later in the season in British Columbia and western Alberta.

This stormy pattern will also likely delay the onset of sustained, spring warming throughout a large portion of British Columbia.

Farther east in the Prairies, near- to below-normal precipitation is anticipated for the upcoming season. The combination of this forecast, below-normal snow pack and the fact that much of southeastern Saskatchewan, southern Manitoba and extreme northwestern Ontario is under moderate to severe drought, the risk of extreme spring flooding later in the season is currently below average. However, it is still very early, and conditions can change quickly in early spring, thus additional updates on the spring flood risk are likely through the season. There is also currently much less water frozen in the sub-surface soil compared to what there was during the winter of 2019-2020.

A secondary storm track is expected to be directed toward the Great Lakes and eastern Canada this spring, which will lead to above-normal precipitation and the risk of significant, early spring snowfall over northern/central Ontario and up into Quebec. The spring flood risk in this region is currently close to average at this point.

The stormier pattern coupled with a continuation of abnormally high water levels, especially on Lake Erie and Lake Huron will keep the risk of near-lakeshore flooding during stormy periods higher than normal through the season. 

Ice coverage on the Great lakes has increased significantly this month, especially on Lake Erie. However, overall ice coverage (all the Great Lakes combined) is still near to below normal, and the prospect for sustained periods of extreme cold the rest of February into March appears to be low at this point. Based on this information, I expect ice coverage to be below average through early spring. 

There is an elevated risk for river flooding and ice-jam flooding in New Brunswick this coming season.

The combination of the projected weather pattern this spring and above-normal SST's in the northwest Atlantic, I expect a milder-than-normal spring for much of Atlantic Canada.