SNOWSTORM TIMELINE: Rapid Snowfall Accumulation & Blowing Snow Will Make Travel Near-Impossible Late Monday Into Tuesday Morning Across Southern Ontario

What will likely be the most notable snowstorm of the season so far is expected to bring a quick, but intense blast of heavy snow to almost all of Southern Ontario. Strong wind gusts in all regions between 40-70km/h will be a big concern and will likely lead to blowing snow and even localized blizzard accumulation. Travel should be avoided until later on Tuesday if possible. Total accumulation but the end of Tuesday will range from 20-35cm in the hardest-hit regions from Windsor/London through the GTA and into Eastern Ontario. For more details on the accumulation, please check out our complete forecast HERE.

Some light snow will continue to be found around the GTA during the noon hour as the first wave slowly tapers off. The second round will begin between 7-10 pm with the heaviest snow reaching the region during the late evening and continuing overnight into Tuesday morning. Hourly snowfall rates of between 3-6cm are possible during the 5-10 hour timeframe so the snow will rapidly accumulate. Snow will become lighter just after sunrise as the system exits the region.

For Southwestern Ontario, the snow will start a little earlier around the dinner hour as the first bands cross Lake Erie and make their way northward. Heavy snow with rates between 2-5cm will be found during the mid to late evening and into the early overnight hours. The heavy snow will transition over to lighter snow just before dawn on Tuesday with some lake effect snow lingering around the Owen Sound and Meaford area past the noon hour.

Eastern Ontario will be the last to see the first bands of the second round reach them which is expected to start around 9-11 pm for most. The light snow will turn to heavier snow especially near the Kingston and Cornwall area closer to the American border where intense snowfall rates near 5cm per hour could be found. These heavier bands will come to an end during the late morning with flurries continuing into the afternoon.

Central Ontario will be right on the edge with this system so areas further to the south and east will see the heavier snow for a longer time. Snow will start during the late evening and continue overnight into Tuesday morning. Again, some lake effect snow will linger around the southern shoreline of Georgian Bay into Tuesday afternoon.