Canada, US: Adverse winter weather conditions forecast across parts of south central Canada and north central US through at least Dec. 1

Adverse winter weather conditions are forecast across parts of south central Canada and north central US through at least Dec. 1. Lake effect snows, ongoing across portions of Michigan, are forecast to expand and intensify downwind of all Great Lakes. Thundersnow is possible in some areas. Hourly snowfall totals up to 7.5 cm (3 inches) are possible. Significant snowfall accumulations are likely through Nov. 30, with up to 1.5 meters (5 feet) of snow downwind of Lake Ontario in northern New York. The combination of heavy snowfall and gusty winds may cause blizzard conditions in places. Hazardous driving conditions are likely across the affected areas due to icy roads and reduced visibility caused by blowing snow.

As of late Nov. 28, the US National Weather Service (NWS) has issued winter storm warnings for northern Michigan and lake effect snow warnings for western New York and far northern Ohio. Winter weather advisories are in place across most of the rest of the affected area.

Environment Canada has issued red snow squall warnings (the highest level on a three-tier scale) off of Lake Nipigon through Nov. 29, off of Lake Superior through the evening of Nov. 30, off of Georgian Bay through early Dec. 1, and off of Lake Huron through Dec. 1. Yellow snow squall watches are in place over most of the rest of the affected area. Officials will likely issue new alerts or update/rescind existing advisories as weather conditions change over the coming days.

Snow accumulations are likely across the affected area. Lesser snowfall totals are possible where sleet and freezing rain mix with snow. In addition to the heavy snow, strong wind gusts could lead to periods of blowing and drifting snow. Sporadic power outages may occur throughout the affected area.

The inclement weather will likely cause widespread ground and air transport disruptions across the affected areas. Traffic and commercial trucking delays are probable along regional highways. Dangerous and challenging driving conditions are also likely on secondary and rural roads as maintenance crews prioritize clearing major routes. Authorities will likely close stretches of highways if driving conditions become too hazardous. Gusty winds will threaten to topple high-profile vehicles throughout the affected areas. Mountain passes and tunnels will probably be closed as a precautionary measure during periods of intense snowfall. The disruptive weather will likely cause delays and cancellations at airports in the affected regions. Heavy, wet snow and strong winds could bring down power lines and trees with foliage.