Thursday, January 21st 2021, 7:30 pm - Periods of snow will continue to impact southern Ontario through Saturday as some of the coldest air of the season settles in.
If you live in a community that saw above-zero daytime highs Thursday, that will be the last above-seasonal temperatures you're likely to see for the foreseeable future. Beyond, colder temperatures are set to flow back into southern Ontario, with shots of lake-effect snow squalls Friday heading into the weekend, with the chance of a meatier shot of snow next week. A closer look, below.
- Chance of wandering snow squalls once again Friday, reaching into the GTA at times but otherwise mostly keeping to the snow belts
- Temperatures below zero Friday, coldest air of the season soon to follow
- Eyes on a possible Texas low early next week
FRIDAY: REPEAT OF SNOW SQUALL POTENTIAL
Though daytime highs once again crept above zero Thursday, a passing cold front brought colder air flowing back into the province, making things feel more January-like for the foreseeable future.
With that colder air in place and a northwest flow getting re-established across the region, lake-effect snow bands will re-develop for Friday primarily for the snowbelts, but reaching into parts of the GTA at times as well.
Poor travel conditions are likely Friday and Saturday across most main highways through the Grey-Bruce and Huron-Perth regions, particularly Highway 21, Highway 8, and portions of the 401 between London and Cambridge. Conditions will also deteriorate along the 400 from the northern GTA through Barrie and Orillia.
As with most snow squalls, accumulations will be highly variable, but some areas through Grey-Bruce and Huron-Perth could see some significant accumulations into Saturday, possibly exceeding 30 cm locally.
WEEKEND: COLDEST AIR OF THE SEASON SO FAR SETTLES IN
A more persistent cold pattern will begin on the weekend across the south, with the threat for some of the coldest temperatures of the season so far. The city of Toronto for example, could actually reach -10°C for the first time this winter.
"If this happens, it will be at least 20 days after the previous latest first -10°C day (Jan. 3, 2016)," says Gillham. "Only twice on record have we gotten into January without having dipped to -10°C and yet this year we are going to get over three weeks into January without reaching -10°C."
While much colder than we've seen, this weekend's temperatures are more typical of late January and really won't be all that far off of seasonal values.
EYES ON POTENTIAL HIGH IMPACT STORM NEXT WEEK
Beyond the weekend, forecasters are watching the potential for a Texas low to approach or track south of the Great Lakes region early next week.
"One scenario keeps the storm well to our south with little to no snow for the Golden Horseshoe. However, it is possible that this storm will track further to the north and become a high impact winter storm for much of southern Ontario," says Gillham, adding that computer models currently range from no snow at all to 10-20+ cm of snow.
Near to slightly below seasonal temperatures are expected to dominate next week.
Be sure to check back for updates as we continue to monitor the potent lake-effect potential and looming storm early next week.