An intense low pressure system has prompted warnings across parts of eastern Ontario and Quebec, with the risk for heavy rain and snow spreading across the region into Thursday.
This system will rapidly intensify as it tracks along the cold front from the eastern U.S. and into eastern Quebec, meeting ‘weather bomb’ criteria as its minimum pressure falls 24 mb in just 24 hours.
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“Given the frozen ground, significant amounts of water due to snowmelt and rain could accumulate on roads and low-lying areas,” says Environment and Climate Change Canada (ECCC) in a rainfall warning already posted for the regions.
Roads and sidewalks may also become slippery, as temperatures drop later Wednesday and the precipitation transitions over to snow. Travel will likely be impacted, so it’ll be important to stay alert to the weather warnings as conditions deteriorate.
Tuesday night into Thursday: Heavy rain picks up, snow over central Quebec
The first round of rain starts in eastern Ontario and southern Quebec Tuesday night, with a brief break Wednesday morning before the second round pushes in.
The greatest intensity in rainfall amounts will be Wednesday afternoon and evening for Ottawa, Gatineau, and Montreal, and then through the evening hours for Sherbrooke and Quebec City.
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A widespread 20-30 mm of rain is forecast into Thursday, with the potential for locally higher amounts up to 40 mm. This could result in some localized flooding in low-lying areas.
“A significant rise in the flow and level of some rivers is also quite possible,” says ECCC.
By Wednesday evening, snow develops on the western side of the system for Mont-Laurier and Mont-Tremblant, Que., and continues into Thursday morning. The heavy, wet snow in central sections of the province could result in power outages.
Flurries could reach as far south as the St. Lawrence river in Ontario Wednesday overnight, with the chance of some brief flurries in Montreal, as well. There is still some uncertainty, however on how far south and east the snow will develop, so it’ll be important to monitor the changes with the forecast.
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Winds will be breezy along the St. Lawrence and Eastern Townships on Thursday, with gusts reaching between 50-70 km/h.
Friday and Saturday will be mostly sunny, but very cold, and possibly the coldest days of the season so far. A system tracking south of the region could bring some light snow and possibly mixed precipitation on Sunday, ahead of mild temperatures that are expected for the first half of next week.
Stay with The Weather Network for more forecast updates and information on your weather across eastern Ontario and Quebec.