First heavy snow of the season in southern Ontario brings travel advisories

Winter weather swept back into southern Ontario Sunday, bringing with it the season's first heavy flurries and snow squalls - and travel advisories.

Environment Canada issued a weather warning for the Barrie-Orillia-Midland region with heavy flurries near Georgian Bay and Lake Simcoe after a steady temperature drop over the weekend.

Snow squalls were expected to last through the day, peaking at noon with rates of 2 to 4 cm per hour. Barrie, Collingwood and Hillsdale could see as much as 25 cm of snow Sunday.

Meanwhile, in southwestern Ontario, Huron-Perth and Grey-Bruce regions were also under an Environment Canada squall warning, where snowfall was expected to last through Sunday night, before weakening Monday.

Environment Canada meteorologist Brian Owsiak said below-season temperatures and cool winds blowing over the Great Lakes have allowed the right weather pattern" for flurries to form.

When there's enough temperature difference between the lakes and the air aloft, that allows snow to develop," Owsiak told the Star. Ontario is one of the few places that gets this lake-effect phenomenon."

Snow is expected to accumulate, melting by Monday night as temperatures hover near zero and 1 C. Heavy snowfall is expected to accumulate over roads and highways north of the region, lasting until the middle of the week.

Environment Canada advises motorists to exercise caution due to shortened visibility and slippery roads. Travel is expected to be hazardous as weather conditions vary considerably from clear skies to heavy snowfall within a few kilometres.

Toronto will hit the negative temperatures early Monday morning after a stretch of above-seasonal temperatures over the past weeks.

Snowflakes fell for the first time in months Sunday morning with light flurries. Environment Canada is forecasting showers for Sunday and flurries for early Monday morning in the GTA.

We are not expecting them to be too heavy or last too long," Owsiak said. But if the temperatures are cooler, there is a risk Toronto can see snow Tuesday night into Wednesday."

Santiago Arias Orozco is a breaking news reporter, working out of the Star's radio room in Toronto. Follow him on Twitter: @SantiagoAriasO6