Travelling in and around the Greater Toronto Area could get "extremely dangerous" this weekend, according to meteorologists, as intense snow squalls threaten to dump as much as 50 cm of the white stuff on some parts of southern Ontario.

A pattern developing over the Great Lakes is "ripe for a prolonged lake-effect snow event" in the days ahead, according to The Weather Network, with communities near the northeastern shores of Lake Erie and Lake Ontario likely to be hardest hit.

Snow squall watches and warnings have already been issued for areas including Barrie, Orillia, Midland, Kingston, Prince Edward County, Parry Sound, Muskoka, Oxford, Brant and Niagara as of Thursday morning, based on the current trajectory of four bands headed moving in our direction.

Toronto shouldn't see more than 5 cm of accumulation over the weekend, based on current predictions, but this could change quickly.

"Snow squalls cause weather conditions to vary considerably," warns Environment Canada. "Changes from clear skies to heavy snow within just a few kilometres are common."

To wit, just across the lake from Toronto, Niagara Falls is expected to see local snowfall accumulations of 30 to 60 cm by Sunday morning. The forecast for nearby Buffalo, New York, is even scarier.

A classic setup for significant lake-effect snow could bring thigh-high snow to parts of southern Ontario by Sunday, a walloping that will significantly disrupt travel through the affected areas. #ONStorm #ONwx #ONSnow https://t.co/sdQyKOE61l

— The Weather Network (@weathernetwork) November 17, 2022

"Higher amounts are possible in the most persistent snow squalls.
Visibilities may be reduced to near zero in heavy snow and local blowing snow," reads EnviroCan's squall watch for Niagara Falls, Welland and the southern Niagara region.

"Conditions are favourable for a prolonged period of significant lake effect snow squalls off of Lake Erie tonight through this weekend. Extremely dangerous travel is expected within these snow squalls."

The storm is expected to hit late Thursday or early Friday, impacting travel conditions across the region well into Sunday.

"Due to the nature of lake-effect snow, storm totals will vary widely over short distances and between one community and another," explains The Weather Network, which warns that some parts of southern Ontario could see "thigh-high snow" by Sunday morning.

"Widespread totals of 25+ cm are possible throughout the region, with localized amounts of 50+ cm possible under the heaviest and most stubborn bands that develop."

Needless to say, this won't be a great weekend for visiting the cottage — unless you're already safely there before the snow squalls hit.