October snow creeps into Ontario as Arctic air plunges south
November-like weather has arrived in southern Ontario as an unseasonable chill descends into the province. Along with the chill comes the threat for frost and snow
This week will bring typical fall conditions across Ontario as multiple low-pressure systems with ample amounts of moisture move through the region. Things will actually be feeling more like November, with blustery and cool conditions taking shape. Lake-enhanced moisture will lead to 30-60 mm of rain for parts of Ontario through Thursday, along with the chance of lake-effect snow in different regions. Will this be the freefall right into winter for the region? See the details on the upcoming pattern, below.
This week: Windy, wet and chilly
Temperatures will plunge across northern sections of the province Tuesday, with some communities struggling to push their daytime high temperatures above the freezing mark.
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Southern Ontario started to see the impacts of the cooldown as well, with conditions favourable for graupel, which was reported in many locales on Monday.
This could occur again on Tuesday and Wednesday this week.
By mid-week, daytime highs in Toronto will only reach the upper single digits, with even chillier conditions expected for folks up towards cottage country.
Wind speeds will strengthen early to mid-week, allowing for a wind chill to kick in and make conditions feel much cooler.
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With the trough in place, some areas are looking at considerable amounts of rain this week. The Lake Huron shorelines could see anywhere from 30-60 mm, 40-60 mm for parts of northeastern Ontario and 20-40 mm on tap for parts of cottage country.
This bout of cold air is more like what you’d expect to see in November than the middle of October. Daytime highs will be five to eight degrees below seasonal with overnight lows will hovering near 0°C.
We're also on the lookout for the chance for snow across the province.
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The low-pressure system will continue to swirl over the Great Lakes, wrapping in cold air with it. Temperatures will be cold enough, and the atmospheric pattern will be favourable enough, so that any precipitation moving through the region could fall as wet snow.
In northern Ontario, snowflakes will fall north of Lake Superior and spread eastwards into Wednesday with wet snow or mixing expected at times. For areas in northeastern Ontario, east of Highway 144, it will be mainly rain that will fall, until Wednesday when cooler temperatures dominate and the precipitation changes over to snow.
"As much as 10-20 cm of snow is possible to accumulate in areas northeast and east of Lake Superior," says Matt Grinter, a meteorologist at The Weather Network.
The low will also prompt rounds of lake-effect showers through mid-week and help push wet snow into some of the higher elevations of southern Ontario, potentially above the escarpment and over the Dundalk Highlands.
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"Even colder temperatures will move into the region Wednesday overnight into Thursday morning, which could bring the first accumulating snowfall for southern Ontario," Grinter adds. "Areas in central Ontario away from Georgian Bay and in higher elevations like Huntsville and Algonquin could see some accumulating snow. Snow brushes and shovels may even be needed."
While the November-like weather will dominate much of this week, forecasters are watching the potential for a much warmer end to the month.
Spectacular fall weather is expected this weekend across the south, with abundant sunshine and well above seasonal temperatures. Daytime highs will reach the mid to upper teens with a few spots possibly hitting 20°C. Warmer than normal temperatures are set to dominate through the final week of October.
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Stay tuned to The Weather Network for the latest forecast across Ontario.
