Canada: Adverse weather forecast across southeastern regions through at least early Oct. 16

Severe weather is forecast across parts of southeastern Canada through at least early Oct. 16. Heavy rainfall, strong winds, and snowfall are expected across parts of the region over the coming days due to a developing low-pressure system. Rainfall amounts of 4-6 cm (1.6-2.4 inches) and snowfall accumulation of 5-10 cm (2-4 inches) are possible in parts of the affected area. 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.

As of early Oct. 14, Environment Canada has issued red rainfall warnings (the highest level on a three-tier scale) for parts of the Fundy coast in New Brunswick and the Gaspe Peninsula in Quebec. Red strong wind warnings are in place for parts of northeastern Nova Scotia and Anticosti Island and parts of the Gaspe Peninsula in Quebec. Red storm surge warnings are also in place for the eastern end of the Gaspe Peninsula. Grey special weather statements for strong winds and heavy rainfall are in place for parts of southeastern Quebec near the mouth of the St. Lawrence River, and grey weather advisories for hazardous travel conditions due to snowfall have been issued for some interior areas of southern Quebec. 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 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. If there is severe damage to infrastructure, repair or reconstruction efforts may result in residual disruptions.