Canada, US: Adverse winter weather conditions forecast across parts of southeastern Canada and the northeastern US through at least early Jan. 4

Adverse winter weather conditions are forecast across parts of southeastern Canada and the northeastern US through at least early Jan. 4. A low-pressure system is expected to bring heavy snowfall across parts of the region over the coming days. Snowfall accumulations of 15-30 cm (6-12 inches) with localized heavier amounts are possible in areas downwind of the Great Lakes. Strong winds and heavy rainfall are also possible across parts of the region. Hazardous driving conditions are likely across the affected areas due to slippery roads and reduced visibility caused by blowing snow.

As of early Jan. 2, the US National Weather Service (NWS) has issued winter storm warnings for parts of northeastern New York and northern Vermont and lake effect snow warnings for parts of northeastern Ohio, northwestern Pennsylvania, and north-central New York. Winter storm watches have been issued in parts of northeastern Ohio and winter weather advisories are in place across much of the rest of the affected area.

Environment Canada has issued red snow squall warnings (the highest level on a three-tier scale) for parts of south-central and southeastern Ontario and red snowfall warnings for parts of southeastern Labrador and southern and south-central Quebec. Red rainfall warnings are in place for parts of southwestern Newfoundland and southeastern Quebec. Red strong wind warnings have been issued for parts of western Newfoundland and northeastern Nova Scotia, as well as red storm surge warnings between Pointe-des-Monts and Gallix in Quebec. Yellow snow squall warnings are in place for parts of southeastern Ontario and grey weather advisories for blowing snow are in place for parts of south-central and southeastern Ontario and southeastern Quebec. Grey special weather statements for heavy rainfall have been issued for parts of southeastern Quebec.

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.