Powerful winter storm forecast for portions of Ontario and Quebec

Last weeks snow should have guaranteed us a white Christmas, but this is Montreal in 2022, and rain and mild temperatures are forecast for Friday. A strong cold front will produce high winds and rain changing to snow Friday afternoon. Travel will be greatly impacted across southern Ontario and Quebec as temperatures plunge back below freezing. (Valley Weather Photo)

Winter officially arrives at 4:47 pm Wednesday, and to welcome it, we have an historic storm taking shape across the central US, powered by the coldest air in decades plunging south from western Canada. How cold? On Tuesday, the mercury dropped to -52C at Rabbit Kettle in the Northwest Territories. This gives you an idea of the depth of the cold air. That air, combined with a fetch of warm moist air from the southeastern US, will generate a powerful low pressure area, expected to "bomb out" as it moves across the lower Great Lakes into southern Ontario. Bombing out is when a low pressure area drops 24mb of central pressure in 24 hours or less. This storm is forecast to drop to as low as 960mb over Ontario.

A strong winter storm will develop over Kansas and move into Ontario on Friday. The system has the potential to be historic with blizzard conditions, strong winds and a flash freeze forecast for many areas. (AccuWeather.com)

In terms of practical weather, a wide variety of impacts are expected across southern Quebec and the metro Montreal region. As the storm moves from Kansas to Ontario, a warm front will lift across southern Quebec on Thursday evening. A mix of snow, rain and perhaps some freezing rain will occur, before the temperature rises above freezing into Friday morning. The warm air will push the high to 6C (43F) in Montreal. By late Friday, a powerful cold front associated with the storm, will sweep across the region, plunging temperatures in a very short period well below freezing. A flash freeze is expected, with rain changing back to snow.

The front will also generate very strong to damaging winds, gusting up to 100km/h in Montreal. The wind will cause power outages and blow around whatever snow is falling. Travel will be extremely difficult Friday afternoon into Saturday across the entire region, including all highways to Ontario, New York and Vermont. Strong winds and snow squalls will continue into Saturday, combined with much colder temperatures and frigid windchill values. The highs Saturday will remain steady in the minus single digits.

Travel will be greatly impacted by this strong winter storm, and power outages are likely in Quebec. Plan ahead and listed to the latest forecast and for any weather warnings.

I will post frequent updates over the next few days.