Canada: Severe weather forecast over parts of southern Ontario and southern Quebec July 16 /update 1

Severe weather is forecast over parts of southern Ontario and southern Quebec July 16. Thunderstorms and heavy rainfall are ongoing across parts of the Ontario Peninsula as of early July 16, and storms are forecast in parts of southern Quebec during the afternoon and evening July 16. Strong winds and hail may accompany storms. Heavy downpours may trigger flooding in low-lying areas, and strong winds could cause property damage and power outages.

As of early July 16, Environment Canada has issued red heavy rainfall warnings (the highest level on a three-tier scale) for Toronto and surrounding areas, as well as central and western parts of the Ontario Peninsula. Rainfall totals of 5-10 cm (2-4 inches) are possible in these areas. Yellow severe thunderstorm watches have been issued for Toronto and adjacent areas to the east in Ontario and across the affected area in Quebec. Winds gusting up to 90 kph (56 mph) are possible during storms. Authorities will likely issue new alerts or update/rescind existing advisories as weather conditions change over the coming hours.

Sustained heavy rainfall could trigger flooding in low-lying communities near rivers, streams, and creeks. Urban flooding is also possible in developed areas with easily overwhelmed stormwater drainage systems. Sites located downstream from large reservoirs or rivers may be subject to flash flooding after relatively short periods of intense rainfall. Landslides are possible in hilly areas, especially where the soil has become saturated by heavy rainfall.

The severe weather could contribute to transport disruptions throughout the region. Floodwaters and debris flows may render some bridges, rail networks, or roadways impassable, impacting overland travel in and around affected areas. Ponding on road surfaces could cause hazardous driving conditions on regional highways. Authorities could temporarily close some low-lying routes that become inundated by floodwaters.

Severe weather may trigger flight delays and cancellations at airports across the affected region. Flooding could block regional rail lines; freight and passenger train delays and cancellations are possible in areas with heavy rainfall and potential track inundation.

Localized business disruptions could occur in flood-hit areas; some businesses might not operate at full capacity because of damage to facilities, possible evacuations, and some employees' inability to reach work sites. Strong winds could also cause power outages.