10-25 cm: Winter strikes back at southern Ontario with winds, snow and cold
Southern Ontario welcomes back winter in a big way on Tuesday, with a significant temperature plunge, blustery winds and snow. Expect hazardous travel in the hardest-hit areas, which could see 10-25+ cm of snow through Wednesday morning
A mild and rainy Monday has quickly changed to snow and cold. Welcome to March, Ontario.
Some areas will see temperatures drop sharply by 20°C to 25°C within 12 hours following the cold front passage--a shock to the system of folks who enjoyed near-20-degree weather on Monday.
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Along with the cold and wind chills will be the return of strong winds and snow, with the heaviest amounts of the white stuff expected in the traditional snowbelts. Some areas are in line to see 10-25+ cm through Wednesday morning.
Be sure to keep an eye on the road conditions before heading out.
Temperature drop and snow follows behind cold front
By Monday evening, winter weather made a quick return. As temperatures fell sharply—by as much as 20-25°C in places like Ottawa, Brockville, and Cornwall—rain transitioned to snow.
Frozen surfaces from rapidly dropping temperatures and refreezing puddles may lead to slick and hazardous conditions, with widespread 5-10+ cm of snow expected from the eastern Greater Toronto Area (GTA) to Ottawa by Tuesday morning.
Black ice threat exists. The rapid cooling behind the cold front will quickly drop temperatures, especially on bridges where the road surface cools more quickly. The precipitation on late Monday could leave the pavement wet before freezing.
Wind chills will be into the negative teens by Tuesday morning all across southern and eastern Ontario, dipping into the -20s in the snowbelts.
Evening commutes could be impacted by bursts of heavy snow.
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Lake-effect becomes more organized and concentrated through Monday overnight, lingering well into Tuesday in the traditional, downwind snowbelts off Lake Huron and Georgian Bay.
Localized accumulations of 10-25 cm possible in the snowbelt regions under an orange-coded snowsquall watch.
Strong winds of 60-80+ km/h across southern Ontario, including the GTA, Niagara, Kingston, and Cornwall may contribute to reduced visibility and difficult travel, potentially resulting in road or school closures on Tuesday.
Razor-sharp snowsqualls are forecast to continue to impact regions downwind of the Huron shores on Tuesday, producing snowfall rates of 1-3 cm an hour.
Kincardine, St. Mary’s, Mitchell, Mount Forest, and Hanover have the highest potential to exceed 15 cm of snowfall.
School and road closures are possible Tuesday in the snowbelts.