Canada: Adverse weather forecast across southeastern regions through at least Nov. 24

Severe weather is forecast across parts of southeastern Canada through at least Nov. 24. A storm system moving up the northeastern United States will bring a mix of heavy rainfall, sleet, freezing rain, and snow across the region as it tracks generally northeastward over the affected area Nov. 22-24. Flooding is possible in areas where heavy rainfall occurs and hazardous travel conditions are likely in areas where more wintry precipitation falls due to slippery roads and reduced visibility caused by blowing snow. Strong winds may cause property damage and power outages in parts of the affected area.

As of early Nov. 22, Environment Canada has issued snowfall warnings (the highest level on a three-tier scale) for parts of southwestern New Brunswick; snowfall accumulations of 10-15 cm (4-6 inches) are forecast in the affected area Nov. 22 before snow transitions to rain late Nov. 22. A Les Suetes wind warning is in place for parts of northeastern Nova Scotia, with winds gusting up to 100 kph (62 mph) possible in this area Nov. 23. A special weather statement for heavy rainfall is in place for Lunenburg, Queens, Shelburne, and Yarmouth counties in southwestern Nova Scotia; rainfall totals of 4.5 cm (1.8 inches) with localized higher amounts are forecast in this area Nov. 22-early Nov. 23. Another special weather statement for heavy rainfall is in place for parts of southwestern Newfoundland, with rainfall totals of 4-6 cm (1.6-2.4 cm) expected late Nov. 23-early Nov. 24. A special weather statement for ice pellets and freezing rain late Nov. 23-early Nov. 24 is in place over central Newfoundland. Officials may update and extend the coverage of weather alerts over the coming hours.

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 northern 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. Authorities may temporarily suspend port operations in coastal areas if strong winds trigger hazardous sea conditions, impacting freight and passenger maritime traffic. Flooding or snow could block regional rail lines; freight and passenger train delays and cancellations are possible in areas that see heavy rainfall and potential track blockages. 

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