Toronto-area snow squalls a prelude to next week’s major storm
Snow started falling across the Greater Toronto Area (GTA) as the sun set on Saturday and easterly winds began whipping up a band of lake-effect snow.
This snow squall developing over western Lake Ontario will bring periods of steady—and occasionally heavy—snowfall from the city of Toronto east along the lakeshores. Plan ahead for rapidly changing weather and potentially dangerous road conditions through early Sunday.
Our weekend dose of snow will serve as a prelude to the major Texas low eyeing Ontario and Quebec heading into next week, which will pack a wide array of disruptive hazards across both Canada and the U.S.
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Snow squalls threaten GTA, area highways this weekend
This lake-effect snow risk will focus on the Greater Toronto Area (GTA) and surrounding regions late Saturday into Sunday. A very narrow band of locally heavy snowfall is forecast to develop, but there is some uncertainty as to where the squall will lock in. The shores of Lake Ontario from Burlington to Oshawa, including Toronto, are all at risk.
Some areas will see conversational snow from this event, while others are at risk for 5-15 cm on the ground by Sunday. The Gardiner, DVP and 400-series highways (404, 400, 410, 427, 401) all stand a risk for slick conditions and slowdowns through Sunday morning.
Here’s a precipitation snapshot for Saturday evening across the GTA, showing the heaviest snowfall impacting the city of Toronto and areas eastward.
Because of the small-scale weather ingredients that generate lake-effect snow, there is still room for change.
Lake-effect snow is characterized as very narrow bands of intense snowfall that can lead to significant accumulations and winter travel troubles. Meanwhile, other centres a short distance away may see no snowfall whatsoever.
We haven’t had much opportunity to flex winter weather driving skills this season, so dicey travel is likely Saturday night through Sunday morning. Leave extra time, take it slow, and give extra space to other motorists if you’re caught driving in the snow this weekend.
Major Texas low is a storm to watch for next Tuesday
The pattern developing early next week is increasingly favourable for a large, high-impact Texas low to develop and track toward Ontario and Quebec late Tuesday into Wednesday.
This will be the first major system of 2024 for Ontario and Quebec and forecasters are growing more confident in its eventual impacts on the region.
EXPLAINER: How Texas lows influence Canadian weather
It’s a classic continent-wide winter storm setup, with a sprawling low-pressure system developing over the central U.S. that’ll draw cold air from the north, warm and humid air from the south, and a tremendous amount of energy to develop in a hurry.
This dynamic storm will feature a little bit of everything from a risk for severe thunderstorms in Florida to heavy rain and snow across Central Canada, threatening travel disruptions on both sides of the border.
Ontario and Quebec can expect a swath of heavy, wet snowfall to develop on Tuesday across southern Ontario, likely transitioning to rainfall through the overnight hours as that Gulf warmth surges over the border.
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The system could bring 5-15 cm of wet snow before the transition to heavy rainfall across the area, making for a sloppy Wednesday morning commute.
Forecasters are confident in a transition to rain across the area due to the centre of the storm likely tracking north of the 401 corridor.
Widespread winds of 40-70 km/h are likely with this storm as it tracks across southern Ontario, with the potential for locally higher gusts along the lakes.
Heavy, wet snow will greet commuters across southern Quebec early Wednesday before an eventual transition to rainfall. Ottawa might see as much as 15-25 cm of snowfall out of this system, but check back for further updates.
The storm track will make all the difference, so be sure to continue to check back this weekend as we nail down your first major storm of 2024.