Cold and strong northwest winds over Lake Huron and Georgian Bay generated local snow squalls in parts of southern Ontario Tuesday morning.
Environment Canada warned of reduced visibility and sudden bursts of heavy and blowing snow.
"A small lake effect band was responsible for the terrible morning commute in Toronto Tuesday," says Dayna Vettese, a meteorologist at The Weather Network. "Motorists faced poor driving conditions near Highway 407/427, but as soon as you got west of that location, brilliant sunshine."
Tuesday morning's commute was a perfect example of how lake effect snow can impact one area, but may not affect another at all.
"Lake effect snow is created as the cold air moves over warmer waters resulting in rising motion, which produces clouds and localized heavy snowfall. We have one of the coldest air masses we have seen in a couple of years and after a long, hot summer and fall, the lakes are warm, creating the perfect conditions for lake effect snow," explains Vettese.
Just a small band of snow can cause a great deal of trouble, so it's important to be diligent about what you will be driving into.
"The Great Lakes often dictate our weather," adds Vettese.
In addition to the snow, frigid temperatures also prompted the City of Toronto to issue an extreme cold weather alert on Monday.
Officials say the alert helps to make people aware of the dangers of staying outside too long in the cold.
An alert is activated when Environment Canada predicts a temperature of -15°C or lower, or -15 or below with the windchill. A blizzard, ice storm or sudden drop in temperatures are other factors officials consider.
During an extreme cold weather alert, street outreach workers focus on getting people inside and providing transportation to shelter or overnight respite.
In addition to the outreach, during an alert Toronto immediately adds 172 shelter spaces to those looking for a shelter bed.
Prolonged exposure to extreme cold can result in hypothermia or frostbite, so anyone seeking shelter or who knows someone that needs shelter from the cold is encouraged to call Toronto city services at 311.
Tune in to the Weather Network in the morning this week for updates on where the snowsqualls are.