New Year Snowstorm This Weekend Takes a Southern Shift Bringing the Potential for Up to 6-12cm of Snow to Southwestern/Eastern Ontario and the GTHA

MAP UPDATED - SAT, JAN 1, 2022 @ 2:50 PM (CLICK HERE TO SEE OUR PREVIOUS MAP)

UPDATED FORECAST (Jan 1 - 2:50 PM)

After reviewing the latest model data this morning, we've decided to make a few adjustments to our snowfall forecast for tonight into Sunday.

This system has been hard to nail down as models have handled it quite poorly. The expected track of this system has shifted around throughout the last few days, but it looks like we're finally getting some consensus on how this will affect Southern Ontario.

The main change we've made to our forecast is tightening the snowfall gradient along the northwestern edge because the latest high-resolution data suggest that the precipitation will track tightly along the Lake Erie/Ontario shoreline and into Eastern Ontario. This has affected the Ottawa Valley, around Lake Simcoe and northern Southwestern Ontario with lower expected snowfall totals compared to our previous forecast.

It also appears that the system will be slightly weaker so we adjusted our legend by reducing the expected snowfall totals by 2-4cm for most areas. We've kept the 12-20cm zone through higher elevations in the Hamilton/Niagara region and the international border in Eastern Ontario.

The snow will start late this evening and continue overnight. We expect the heaviest snow to occur during the morning hours on Sunday. It will begin to clear out by the afternoon (or evening for Eastern Ontario).

OLD FORECAST DISCUSSION (NUMBERS MAY BE INACCURATE)

It appears that Mother Nature will deliver a wintery blast of snow to much of Southern Ontario to start the New Year. The system responsible for this snow will begin to enter Southern Ontario just during the late afternoon or early evening starting with the Windsor area. This persistent snowfall will spread to the northeast reaching the GTA just before midnight and Eastern Ontario during the overnight.

As we covered in our preliminary forecast, the exact impact of this system will depend on the track. The latest data has shifted the system further to our south which means there have been some changes to the expected snowfall totals. Due to the southern shift, we expect that we will stay on the cold side of the system and any mixed precipitation will likely remain south of the border. There could be a few hours of mixed precipitation along the Lake Erie shoreline and around the Niagara region, but they should quickly change over to snow.

It should be noted that there is some significant disagreement in the models in regards to exactly how far south this system will track. The American models appear to have more of a consensus between them which we’ve gone with them in creating our forecast. The show a slightly more northern track which would bring widespread accumulating snow to all areas to the south and east of Lake Simcoe. However, the Canadian model wants to take the snow even further south which would reduce snowfall totals even more to our north and perhaps even through the GTA and Southwestern Ontario.

With either scenario, we should still see the Niagara region and Eastern Ontario along the St. Lawrence River picking up at least 10cm of snow. There could be some underachievement in the snow totals on the northern edge of our 8-16cm zone should the more southern track be accurate. The ‘winners’ in terms of the highest snow totals from this event appear to be the higher elevations around Hamilton thanks to some lake enhancement off Lake Ontario. This area has the potential to exceed the 15cm mark. Another zone that includes Extreme Eastern Ontario along the International border including Kingston, Brockville and Cornwall may also see some totals near 20cm.

Otherwise, we’re looking at general totals ranging from 8-16cm from Southwestern Ontario through the GTA/Niagara region and into the Ottawa Valley. Again, keep in mind this is based on the more northern track and could be lower. The potential accumulation will drop off the further to the north you are in Southern Ontario. Those through Central Ontario and into Northeastern Ontario will be lucky to see even a few centimetres of snow from this storm.

Snowfall will continue overnight and into Sunday. There will also be some strong wind gusts ranging from 25-50km/h which may create blowing snow conditions out on the roads. Be sure to take your time and drive according to the conditions. We expect to see the snowfall tapering off late Sunday afternoon for those further west and early evening in Eastern Ontario.