Canada: Adverse winter weather weather conditions forecast across southeastern regions through at least Dec. 22

Adverse winter weather conditions are forecast over parts of southeastern Canada through at least Dec. 22. A powerful winter storm system that may undergo explosive cyclogenesis known as a weather bomb is expected to bring heavy snowfall and strong winds across parts of Atlantic Canada, with freezing rain and heavy rainfall possible in places. Snowfall accumulations of 10-30 cm (4-12 inches) and winds gusting up to 100 kph (62 mph) are expected across parts of the region, with rainfall totals in excess of 6 cm (2.4 inches) and significant freezing rain possible in parts of Newfoundland. Separate from this weather system, lake-effect snow is also forecast across parts of the Ontario Peninsula Dec. 20-21, with accumulations of up to 10 cm (4 inches) possible. Hazardous travel conditions are likely across the region due to reduced visibility caused by blowing snow.

As of early Dec. 20, Environment Canada has issued the following warnings:

• Red snowfall warnings (the highest level on a three-tier scale): Across mainland Nova Scotia.

• Red winter storm warnings: Parts of far southeastern Quebec.

• Red heavy rainfall, freezing rain, and strong wind warnings: Parts of southern Newfoundland.

• Yellow snow squall warnings: Parts of southeastern Labrador, northern Newfoundland, and the Ontario Peninsula.

• Grey special weather statements and weather advisories for snowfall and strong winds: Across much of the affected area.

Officials could update and extend the coverage of weather alerts over the coming hours and days.

Snow accumulations are likely across the affected region, especially at higher elevations. Lesser accumulations are possible where sleet and freezing rain mix with the snow, and precipitation is less intense. In addition to the heavy snow, strong wind gusts will likely lead to periods of blowing and drifting snow in some areas. Sporadic power outages could occur throughout the affected region.

The winter weather will likely cause ground and air transport disruptions across the region. Traffic and commercial trucking delays are probable along regional highways. Dangerous and challenging driving conditions are likely on secondary and rural roads in the affected states as maintenance crews prioritize clearing major routes. Authorities will probably close stretches of highways if driving conditions become too hazardous. Flight delays and cancellations are likely due to ground stops and deicing operations at regional airports.