Ontario: Dangerous travel in snow bursts, big arctic chill
Wednesday, November 21, 2018, 9:00 AM - The systems aren't big, but they're enough to tangle with southern Ontario commutes, especially with wet snow and falling temperatures making for icy roadways. There's a risk for dangerous travel amid lake-effect snow squalls on Wednesday as well with a BIG chill prompting the season's first extreme cold weather alerts in some major cities. More on just how frigid things get (think January) and where the snowiest commutes will be, below.
- Snow squall watches in effect along shores of of Lake Huron, Georgian Bay
- Widespread snow showers expected through Wednesday with weak systems
- Coldest air of the season into province Tuesday through Thursday
- Milder, potentially stormy next weekend
WATCH BELOW: SNOW TIMING
SNOW, SQUALLS AND DANGEROUS COMMUTES
Wednesday might feel like an instant replay for some commutes, especially north and east of the GTA, the Huron-Perth region, and down the 401 corridor to London as a cold front cuts through. While the burst of snow with the front is expected to be over quickly, we're still looking at the potential for light accumulations along a band starting in the pre-dawn hours through cottage country, and reaching the Niagara Peninsula and and London by noon. That sets the stage for that quick trace-to-few-centimetres to fall in less than an hour -- possibly less than half an hour -- as it passes over any one spot, and that could make for some dicey driving conditions once again.
TIMING OUT YOUR AFTERNOON COMMUTE, YOU MAY WANT TO LEAVE WORK EARLY
That isn't all of the snow in the cards for Wednesday, however, as behind the front gusty winds from the north-northwest will set up a fresh round of lake-effect snow streamers off of Lake Huron and Georgian Bay -- streamers that are likely to target the afternoon and evening rush hour for many, particularly along the 401 corridor near London, along the shores of Lake Huron, and north of Toronto up the 400 toward Barrie.
It's possible squalls will also be strong enough to send snow right into the GTA around the dinner hour with 5+ cm of snow not out of the question in places like Markham and Scarborough.The band will continue to shift west into the western GTA including Mississauga and all the way to Burlington with 1-3 cm possible in these places.
"The squalls and strong winds will produce difficult and dangerous travel south of Georgian Bay," says Weather Network meteorologist Dr. Doug Gillham.
Shifting winds should bring an end to the squalls by early Thursday.
RECORD COLD TEMPERATURES SEND US RIGHT INTO JANUARY
While this week's systems are lightweights in terms of actual snowfall amounts, they'll pack a punch when it comes to tumbling temperatures, ushering several reinforcing waves of Arctic air down into the province.
Under the core of the cold air, overnight lows will dip to the -20C mark over northern Ontario Wednesday -- and that's without the windchill making it feel more like -30. Southern Ontario gets off lightly by comparison, but it'll still be some of the chilliest air of the season so far, with overnight temperatures creeping down to near -10 by Thursday morning.
"Daytime high temperatures will be early in the day, then fall well below freezing for the rest of the day on Wednesday, making for colder than seasonal conditions even more mid-January!," says Gillham. "Record cold is likely Wednesday night with temperatures dropping into the minus teens and a few spots away from the lakes reaching -18°C with a wind chill into the -20s."
FIRST EXTREME COLD WEATHER ALERT OF THE SEASON
These frigid temperatures are not only cold enough to send shivers down you're spine, they're cold enough to trigger the first extreme cold weather alerts of the season. The city of Toronto issued the alert early Wednesday ahead of the tumbling temperatures. The Medical Officer of Health will issue this alert when a temperature of -15°C is forecast.
During extreme cold weather conditions, residents are urged to visit vulnerable family, friends and neighbours.
TEMPERATURES DO RECOVER
The good news? The temperature deep-dive doesn't seem here to stay (at least, not yet). A stronger fall storm is expected to take aim on the Great Lakes by the end of this week, and with it comes a push of milder air from the south, and a few days of more moderate temperatures -- possibly even above seasonal.
"But this will be accompanied by widespread rain later Saturday and Saturday night and the showers could linger into Sunday," says Gillham.
Looking ahead to next week, another significant system is on route, with rain the more likely precipitation type. If temperatures end up colder than currently expected however, we could be looking at a significant wet snow event for parts of the region to start the week.