Return to Winter Across Southern Ontario on Tuesday With Accumulating Snowfall Up to 6-12cm

It has been a slow start to the winter season overall with parts of the province only seeing the temperature dip to -10°C or colder for the first time this season in the last week. The first few weeks of 2021 have been no exception with very little in the way of accumulating snowfall or traditional winter-like weather. We have seen a few systems make their way through Central and Eastern Ontario along with some localized snow squall activity within the snow belts. For Southwestern Ontario and into the GTA, the last major snowfall was actually around Christmas. However, that is expected to change as we head into Tuesday with an approaching system that will bring light to moderate snowfall to a wide swath of Southern Ontario. The precipitation won’t be overly intense and it will taper off by early Wednesday so significant impacts aren’t expected with maybe as much as 6-12cm of snowfall accumulation.

We’ll start to see the first bands of snowfall enter the province from Michigan during the mid to late morning hours on Tuesday with Windsor and Sarnia first in line for the snow. The system will spread to the east throughout Tuesday reaching the GTA by the afternoon and Central/Eastern Ontario around the dinner hour. This will continue into the evening and past midnight before slowly clearing out from west to east during the early morning on Wednesday. By dawn on Wednesday, it should be all cleared out except for some flurries through Eastern Ontario

The heaviest accumulation from this system will stretch from Lake Huron through the GTA and into parts of Eastern Ontario. Widespread totals ranging from 6-12cm are expected although a few localized pockets particularly through the Western GTA and into the Dundalk highlands which may see totals near 15cm. Lesser amounts are on tap for the more northern section of Central Ontario where between 2-6cm of accumulation is possible. For areas near Lake Erie and into Extreme Southwestern Ontario like Windsor, there is some disagreement in the models on exactly how much snowfall could fall with some suggesting near 8-10cm while others show less than 4cm. For that reason, we’ve gone with 2-6cm although note that the overachieving potential is there.

After this system, the rest of the week should be fairly quiet but the very cold air will return later this week and especially over the weekend. This could turn back on the lake effect snow machine starting Friday which we’ll be closely monitoring.