Environment Canada has issued a snow squall watch covering London, Middlesex, and most of southwestern Ontario ahead of an incoming system of significant lake effect squalls and frigid temperatures.
In London-Middlesex, the watch replaces an earlier special weather statement from the weather agency that warned the region would see its first ‘significant lake effect snow event of the season’ later this week.
According to the weather advisory, squalls will develop late Thursday as a cold front moves through and as brisk northwest winds develop over Lake Huron and Georgian Bay. Forecasters say the squall system, which will also continue Friday, will also bring with it the coldest air of the season.
The squalls will come ashore in the evening hours, affecting many communities in southwestern and central Ontario, the weather agency said.
“Latest indications suggest there is potential for a strong snowsquall with significant accumulation from Georgian Bay into Simcoe County, and another strong accumulating squall from Lake Huron into Huron, Middlesex, and Lambton counties,” read the advisory.
Visibility is expected to be poor on the roads, and snowfall amounts could range around 5-10 centemetres, said AM980 Weather Specialist John Wilson.
“The snow squall action (happens) when Arctic air comes across the Great Lakes. It’s the difference between the air temperature and the water temperature, and if it’s more than about nine degrees Celsius, that means that snow squalls can form, and it’s going to be a pretty big difference tomorrow,” said Wilson.
Wilson says the bigger the temperature difference, the more severe the snow squalls. As for where and when the squalls land, that will depends on the wind.
“Tomorrow it’ll be a westerly wind taking the flurries and squalls into Huron-Perth and southern Grey-Bruce, mainly,” said Wilson. “Then that wind turns northwesterly and Friday or even Thursday night it’s London-Middlesex’s turn for squalls.”
Environment Canada advises motorists planning to travel Thursday night through Friday to be prepared for hazardous driving conditions due to heavy and blowing snow.
With the daytime high expected to generally stay below the freezing mark over the next two weeks, in addition to more snowfall, it appears Old Man Winter may be laying the foundation for a white Christmas.
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With files from Natalie Lovie