US, Canada: Adverse winter weather forecast across parts of the northeast US and southeast Canada through at least March 11

Adverse winter weather is forecast across parts of northeastern US and southeastern Canada through at least March 11. A storm system is expected to move northward across the region through March 11, bringing heavy rainfall, snowfall, and thunderstorms. Heavy downpours may trigger flooding in low-lying areas, and strong winds may cause property damage and power outages. Authorities will likely issue new alerts or update/rescind existing advisories as weather conditions change over the coming hours.

As of March 10, the US National Weather Service (NWS) issued various warnings, including warnings for winter storms, high winds, freeze conditions, floods, and coastal flood advisories for parts of Connecticut, Maine, Maryland, Massachusetts, Michigan, New Hampshire, New Jersey, New York, North Carolina, Pennsylvania, Ohio, Tennessee, Vermont, Virginia, Washington DC, and West Virginia. Parts of New England are expected to experience heavy wet snow up to 15-30 cm (6-12 inches), and strong winds, especially over the higher elevation areas.

As of March 10, Canadian authorities have issued red storm systems, winter storm, heavy snowfall, and rainfall warnings across parts of Quebec, New Brunswick, Newfoundland and Labrador, Nova Scotia, Ontario, and Prince Edward Island. The heaviest snowfall is expected in the northern areas, with accumulations up to 40 cm (16 inches) expected with potential rates of 2-4 cm (0.8-1.6 inches) per hour. The heaviest rainfall is expected in the southern areas, with forecasted total rainfall amounts of 20-30 mm (0.7-1.1 inches).

The storm system could produce rounds of heavy precipitation (including rain and snow) and strong winds across the affected area. Where precipitation falls as rain, flash and areal flooding is possible. Such flooding is possible in low-lying communities near watercourses and other large bodies of water, as well as in urban areas with easily overwhelmed stormwater drainage systems. Sites located downstream of large reservoirs may be subject to flash flooding after relatively short periods of intense rainfall. Precipitation could fall as snow in parts of the affected area over the coming days. Wind gusts could cause blowing and drifting snow; decreased visibility is likely in these areas.

Floodwaters and related debris may render some bridges, rail networks, or roadways impassable, impacting overland travel in and around the affected area. Flooding in urban areas could also result in significant traffic congestion. Heavy snow will likely make driving hazardous in some areas; authorities could implement temporary road closures or detours in such locations.

The disruptive weather will likely cause some delays and cancellations at airports in the region. Flooding or snow could block regional rail lines; freight and passenger train delays and cancellations are possible in areas that see heavy rainfall or snowfall due to potential track blockages.

Disruptions triggered by inclement weather and resultant hazards, such as flooding or snowfall accumulations, could persist well after conditions have improved - it could take days before any floodwaters recede and/or officials clear debris. Repair or reconstruction efforts may result in residual disruptions if there is severe damage to infrastructure.