Wet, but milder days in Ontario will be followed by lake-effect snow
If you need put up holiday decorations on the lawn or the outside of the house this weekend in southern Ontario, Saturday will be the better of the two days as a rainy system will follow on Sunday.
A major storm rolling up the East Coast will fling clouds and moisture over the border to end the weekend, bringing widespread showers to the area.
Cold air blowing in behind the system will kick off a fresh round of lake-effect snow for southern Ontario.
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A major storm developing over the Gulf of Mexico will gradually make its way up the Atlantic seaboard on Sunday and Monday, producing high winds and drenching rains along its path.
We’ll see some of that moisture seep north of the border during the day Sunday, fuelling a risk for showers across much of southern Ontario to end the weekend.
Showers will build in through Sunday morning across the southwest, spreading into the Greater Toronto Area (GTA) and east by the afternoon. Rainfall totals will vary across the region, with mostly 5-10 mm, but the Niagara and Muskoka regions could see 10-20 mm.
This is only the system’s opening act, with a flip to more wintry conditions to start the week.
The deepening storm over the U.S. East Coast will graze eastern Ontario on Monday with heavy and persistent showers across the region. Some areas, such as Cornwall and Brockville, could see up to 60 mm of rain from this system.
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As the storm tracks through, northwesterly flow will drag chillier air across the Great Lakes, leading to the potential for lake-effect snow squalls over parts of southern Ontario for Monday.
The absence of Arctic air means that temperature gradients between the surface and the lower atmosphere are muted, which will serve to limit snowfall totals expected from Monday’s squalls. Even so, commuters should plan for potential travel delays Monday evening as conditions rapidly change over short distances.
Temperatures will settle back to seasonal by Tuesday, with milder air favoured to move through the region again later next week.
Stay with The Weather Network for the latest on conditions across Ontario.
