Canada: Severe thunderstorms forecast over parts of southern Ontario July 16

Severe thunderstorms are forecast over parts of far southern Ontario July 16. Conditions are favorable for the development of dangerous thunderstorms capable of producing very strong wind gusts, large hail, and heavy rainfall in the region. As of early July 16, Environment Canada has issued a severe thunderstorm watch across Elgin, Lambton, and Middlesex counties. Winds gusting up to 90 kph (56 mph) and rainfall totals of up to 5 cm (2 inches) are possible in the affected area. 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.