Several systems and the lake-effect machine will generate multiple rounds of snow in Ontario this week, so prepare for some tricky travel at times.
A stalling low over Lake Superior will give big totals downwind of some of the Great Lakes. Meanwhile, a stubborn low will linger over Lake Ontario from Sunday to Tuesday, bringing periods of unsettled weather.
RELATED: Great Lakes see a more than 500 per cent increase in ice coverage
The end result is varying amounts of snowfall this week, ranging from 10-20+ cm of snow near Lake Superior to next to nothing (1-3 cm) for the Greater Toronto Area (GTA) through Tuesday morning.
Expect slower, slippery commutes this week, even with the lighter amounts. Travel will become more difficult in the harder-hit areas.
Travel impacts with bursts of snow this week
With most of the Great Lakes free of ice, the warmer surface water continues to provide instability to sustain low-pressure systems, keeping them stationary.
Sunday evening Ontario precipitation timing
The stronger jet stream remains farther south, so Lake Superior will continue to inject heat and moisture into the atmosphere, making the low appear anchored over the area for the next 24 hours.
Snow will swirl around Lake Superior Sunday with the developing low, spreading light-to-moderate amounts across the region.
RELATED: Arctic air onslaught coming to a Canadian city near you
Monday afternoon Ontario precipitation timing
Snowfall across southern Ontario, associated with the warm front, will be more sporadic, but organized snowfall is forecast along the shores of Lake Huron by Sunday evening.
The GTA largely avoids accumulation, but locally 1-3 cm is possible.
As cold air wraps around the low on Monday, some lake-effect bands are likely for the Bruce Peninsula, Collingwood and areas east of Georgian Bay.
Ontario snowfall map through Tuesday morning
Wind gusts up to 60 km/h along Lake Huron and Georgian Bay, while wind gusts up to 70 km/h are possible along the northern shoreline of Lake Erie.
Expect blowing snow around shorelines, roadways and open fields. The worst impacts will be largely in the snowbelts and across northern Ontario, where travel will be locally challenging.
Projected snowfall amounts:
Southern Ontario snowfall forecast crop through Tuesday morning
On Tuesday, lake-effect snow will continue thanks to the colder air overhead, spilling into Wednesday.
Will that be the last of the snowfall this week? It will not.
A Prairies trough will sweep in from northern Ontario on Thursday, bringing in another few centimetres of snow here and there through southern Ontario.
And then we get another Lake Superior-tracked-in low from the Prairies, a clipper this time, on Friday, bringing another round of winter weather. However, with the northern storm track, the GTA will once again dodge anything significant.
Thursday temperatures and icons Ontario
Temperatures will become quite cold for the middle of this week, but then temperatures will rebound late week and on the weekend to near-seasonal values.
DON’T MISS: Ontario cold snap likely to be Toronto’s longest in at least three years
A rather cold, wintry pattern is expected into the fourth week of January, but a much milder pattern should develop for the first two to three weeks of February, potentially starting during the final few days of January.
WATCH: Snow falls on London, Ontario as squalls ramp up
Click here to view the video