Monday, November 30th 2020, 8:27 pm - A multi-day snowfall event threatens to dump 30+ cm over parts of Ontario through Wednesday, with hazardous travel expected in hardest-hit areas.
The start to December will certainly have the look and feel of winter, as a sluggish, strong Texas low will deliver a wallop to parts of southern Ontario. Tuesday will see the heaviest snow occur, with some areas in line to receive 30+ cm by the time it eases off Wednesday. Expect travel to be tricky in the south, even dangerous across the hardest-hit areas, with poor visibility and rapidly changing road conditions resulting from blustery winds and heavy snow. Snowfall, winter storm warnings, and special weather statements are in place. More on the timing and impact of the snow on Tuesday, below.
- Widespread snow continues through Tuesday, dangerous road conditions likely
- System pushes out by Wednesday, more snow flurries and near seasonal temperatures round out the week
- Temperatures will be somewhat changeable, but near seasonal, for the second week of December
TUESDAY: SECOND ROUND OF WINTRY WEATHER, HEAVY SNOW TO CREATE DIFFICULT TRAVEL
By Tuesday morning, most of the precipitation will have switched to snow in southern Ontario. A second wave of moisture from the sluggish storm will push the dividing rain-snow line into the GTA. Areas in the eastern sections will mainly see rain continue.
Total snow and rainfall totals with the system will vary across the province, depending on location and dividing line of the precipitation.
As cold air pushes into the region, this will allow for strong, northwesterly winds to develp. Gusts near 70 km/h are possible in the afternoon and evening near Lake Huron and Georgian Bay. Winds will still be gusty in the GTA, though not nearly as strong.
Coupled with the snow, this could create hazardous driving conditions, even in areas with less intense snow bands.
Snowfall warnings are in effect for Dufferin County, Simcoe County, Elgin County, Grey-Bruce, London-Middlesex and Sarnia-Lambton regions, where the heaviest accumulations are expected through Wednesday morning. There is also a winter storm warning for Grey-Bruce, and special weather statements peppered across the south.
"Be prepared to adjust your driving with changing road conditions. Rapidly accumulating snow could make travel difficult over some locations," Environment Canada warns.
"Visibility may be suddenly reduced at times in heavy snow. If visibility is reduced while driving, turn on your lights and maintain a safe following distance."
SNOW ON SOUTHERN ONTARIO ROADS IS JUST THE BEGINNING OF THIS MARATHON
SNOW TOTALS: THREAT FOR 30+ CM FOR SOME
Parts of Ontario are in for substantial amounts of snow. Areas near the southern tip of Georgian Bay could see 30-50 cm of snow, the Algonquin Highlands and areas west of London, south of Lake Huron, could see 20-30 cm, and 15-25 cm of snowfall is expected for areas atop the escarpment and north of Highway 9.
Meanwhile, 10-20 cm is forecast in extreme southwestern Ontario, 10-15 cm between London and Hamilton, and 5-10 cm for most of the GTA. About 5 cm is expected for downtown Toronto, but as much as 10 cm could fall in areas away from the lake.
As for rainfall, while only the eastern areas will see rain Tuesday, accumulative totals from the low will hit 20-30 mm for the GTA, and along the eastern shores of lakes Erie and Ontario, and up to 20-40 mm for eastern sections of the province, where precipitation over the duration of the multi-day event will stay mostly as rain.
Effects from the low-pressure system is expected to move east of the province on Wednesday morning, but there will be some wraparound, lake-effect flurries on the backside of it, and blustery, cold conditions, through the afternoon.
Beyond, the unsettled weather will hang on with more snow-showers late-week and on the weekend, resulting from multiple fronts pushing across the region. But no major accumulations are expected. Temperatures will be somewhat changeable, but near seasonal, for the second week of December. Typical early winter weather will return for for the middle of December.
Thumbnail courtesy of Doug Bell/Ridgetown, Ontario.
Be sure to check back for updates on this impactful multi-day storm.