Potential Snow and Ice Storm Threatens to Bring Significant Disruptions Across Southern Ontario Starting Wednesday

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Forecaster: Brennen Perry

Published: Sunday, February 19, 2023


The concern is growing over a system expected to affect Southern Ontario as early as Wednesday afternoon and continuing into Thursday. The two main stories expected to dominate with this system’s impact on our region will be the heavy snow to the north and prolonged freezing rain to the south. Total snow accumulation could approach 20-30cm in the hardest-hit locations by the end of Thursday. Significant ice accretion is possible in the areas that see freezing rain with up to 10-25mm of accretion.

Where the mixing line is located will dictate who sees what in terms of precipitation. Most of the latest models agree on a rough track that could put much of Southern Ontario on the snow side of the storm north of a line from Goderich and Toronto. Those closest to the mixing line will experience a mix of ice pellets and snow with total accumulation ranging from 10-20cm including both snow and ice pellets. And further to the north including Central and Eastern Ontario, we are expecting snow to be the main concern with up to 15-30cm of accumulation possible. Do note that there is some uncertainty on how far north the moisture associated with this system will get. So it’s possible that if the system tracks further to the south, those in the far north of our forecast region including Sudbury, North Bay, Algonquin Park and Ottawa will see lower snowfall totals.

Meanwhile, those to the south including Windsor, Sarnia, London, K/W, Hamilton and Niagara will see a mix of ice pellets and heavy freezing rain. This freezing rain could be quite persistent lasting from Wednesday evening through to Thursday afternoon. Almost 12-16 hours of freezing rain will surely lead to a significant impact in the affected regions including making travel near impossible and potential power outages! This will also be followed by some strong to damaging winds late Thursday into early Friday which could lead to even more damage from ice-covered surfaces.

As this storm is still several days away, we can’t get into too many details on the exact timing as that will likely shift around as we get closer to Wednesday. However, it appears likely that the worst conditions will occur during the evening and overnight hours on Wednesday continuing into Thursday. As a result, expect bad travel conditions for the evening commute on Wednesday and the morning commute on Thursday. This will almost certainly lead to widespread school bus cancellations for Thursday.

We will be closely following the latest data over the next few days and will have a more detailed forecast including exact timing and accumulations. As mentioned, there is still plenty of time for the models to change so expect to see at least some changes in terms of location and overall accumulation. We hope this does change as the current scenario doesn’t look good on the effects it could have on Southern Ontario.


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