Canada’s federal weather agency says significant rainfall and unusually higher temperatures have increased the risk of flooding across several provinces, especially parts of the country that are recovering from last week’s snowstorm.
The areas that saw more snow accumulated during the pre-Christmas storm are at higher risk of flooding as the snow melts in conjunction with the rain, Environment Canada meteorologist Brian Owsiak told The Globe and Mail.
In Ontario, this applies to areas near Lake Huron, Georgian Bay and the eastern region of the province. Environment Canada issued a rainfall warning Saturday morning, and predicted between 20 to 30 millimetres in several parts of the province, including Toronto, with more precipitation on the way. Mr. Owsiak said Canadians should expect flooding in low-lying areas and be prepared for minor problems for commuters, adding he did not expect it to become a concern for those in Southwestern Ontario or the Greater Toronto Area.
Environment Canada has issued similar warnings for much of southern Quebec, expecting a total of 25 to 40 millimetres of rain until tomorrow morning and warning residents about the dangers of heavy downpours – which can cause flash floods and water pooling on roads, and possible localized flooding in low-lying areas.
A special weather alert is in effect in Newfoundland and Labrador and will remain until Monday, where some areas could see up to 50 millimetres of rain and up to 10 centimetres of snow. Several parts of the province, including the St. John’s area, Avalon Peninsula North, Clarenville and surrounding areas, Bonavista Peninsula, Bay of Exploits, and central and northeastern Newfoundland will see “significant” rainfall Sunday ending with periods of snow early Monday, Environment Canada said.
Two counties at the southern tip of Nova Scotia, Shelburne and Yarmouth counties, are also expecting “significant” rainfall, between 25 to 30 millimetres into the new year.
In British Columbia, Environment Canada has issued a winter-storm warning in Haines Road from Pleasant Camp to Chilkat Pass, which is expected to begin Sunday and last through Monday. It cited a “a moisture-laden slow-moving frontal system” that is expected to accumulate 40 to 60 centimetres before the snow tapers off Monday night.
Fluctuating temperatures are also expected throughout much of January, with forecasts rising into the lower double digits – well above temperatures such as 0 C or -1 C, which are considered average weather for the month.
“It isn’t impossible to get these fluctuations, even in the middle of winter, but it does look like we are going through quite a mild stretch – even by typical standards,” Mr. Owsiak said.
Using Toronto as an example, he said warmer temperatures, which reached 13 C in Toronto on Friday, and have remained at 7 C throughout Saturday afternoon with an overnight low of 2 C, are expected to last until at least Thursday.
By the end of next week, Mr. Owsiak said Ontario should see a “cool down” for several days that will reflect more seasonal temperatures, such as -1 C or -2 C during the day, and -9 C or -10 C at night. This weather is not expected to last: By next weekend, he said the temperatures will likely perk back up.
These ups and downs are due to a warmer weather pattern that will see a “southernly flow” of milder air move from the United States through Northern Canada, Nunavut and the Northwest Territories, Mr. Owsiak said. He added that colder air typically reserved for January is locked up in the Arctic, and will remain that way for the foreseeable future until the weather pattern changes and brings the cold air down to Southern Ontario.
“If the averages are near 0 C or below, then we’re getting a lot more of the warm southerly air versus the air of the Arctic, which we would more typically see this time of year.”
The winter storm that recently hit Ontario led to icy conditions, with rain turning to snow and flash freezes. High winds resulted in blowing snow across the region and near-whiteout conditions on many major roads, resulting in highway closures and a train derailment that forced the shutdown of Via Rail Canada routes. Major cities such as Toronto and Ottawa racked up 10 to 15 centimetres of snow.