THUNDER BAY -- The Weather Network expects that northwestern Ontario residents will be forced to bundle up more than usual this winter, with a letup partway through the season.
Its long-range forecast for Canada says La Nina, the buildup of cooler-than-normal water off the west coast of South America, will bring a winter with "two distinct personalities."
It will start, it says, with periods of "high-impact weather and an impressive amount of snowfall."
Referring specifically to northwestern Ontario, the private forecasting agency believes that "The cold will be the bigger story...with colder than normal temperatures expected. However, the pattern will relax at times with an extended period of milder weather expected mid-winter," which the rest of the country should also enjoy.
Right now, the general expectation is that La Nina will be weak-to-moderate in scope this year.
Environment Canada's December forecast for Thunder Bay includes seasonal or slightly colder-than-normal temperatures, with average snowfall, for the end of November into December.
But meteorologist Geoff Coulson said "It's been particularly difficult to look much beyond the month of December, due to significant variability among various forecast models for January and February."
Coulson cautioned that there is a lack of consensus on the part of global climatologists on how severe La Nina will actually be.
He noted that previous occurrences have brought colder winters to the prairie provinces, in particular, and that "sometimes that activity can spread into northwestern Ontario as well."
However, the records show that La Nina's impact on Thunder Bay is inconsistent.
Despite a moderate La Nina in the winter of 2011-2012, Thunder Bay experienced a milder-than-usual winter and significantly less snowfall than normal.
