Canada, US: Adverse winter weather conditions forecast across parts of southeastern Canada and the northeastern US through at least March 22

Adverse winter weather conditions are forecast across parts of southeastern Canada and the northeastern US through at least March 22. Lake-effect snow is expected in some areas around the Great Lakes March 20 before a developing low-pressure system spreads across northern New England and southern Quebec overnight March 20-21. A separate low-pressure system is expected to move out of the northern plains over the Great Lakes March 22. Snowfall accumulations of 5-35 cm (2-14 inches) and winds gusting up to around 80 kph (50 mph) are expected across the affected area. 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 early March 20, Environment Canada has issued red snowfall warnings (the highest level on a three-tier scale) for parts of the Gaspe Peninsula in southeastern Quebec and red snow squall warnings for parts of southern Ontario around Parry Sound. Yellow snow squall warnings are in place for parts of southern Ontario, and special weather statements and weather advisories have been issued for parts of Ontario around Sault Sainte Marie and parts of southern Quebec along the US border and around Sept-Iles.

The US National Weather Service (NWS) has issued winter storm warnings for parts of northern New York, and winter storm watches for parts of central and eastern Maine. Winter weather advisories are in place for parts of northern Michigan, far northwestern Pennsylvania, and northern New York.

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.