Residents of Ottawa and surrounding areas are on high alert as severe thunderstorms, accompanied by a risk of tornadoes, are forecast for Thursday afternoon and evening. This follows a day of record-breaking rainfall on Canada Day that caused significant flooding and power outages across the city. Environment Canada has issued severe thunderstorm watches for the region, warning of conditions favorable for the development of storms capable of producing damaging wind gusts of up to 100 km/h, large hail, and heavy rain.
The tornado risk is a significant concern, particularly for areas in Eastern Ontario, including the Ottawa Valley. This comes as the region continues to grapple with a persistent heatwave, with temperatures expected to reach up to 35 degrees Celsius, offering little relief overnight with minimum temperatures around 21 to 25 degrees Celsius. The combination of heat and humidity also raises concerns about deteriorating air quality.
Yesterday, Ottawa experienced its rainiest July day on record, with 118 millimetres of rain falling by midnight, overwhelming drainage systems and leading to widespread basement flooding. Ottawa Fire Services responded to hundreds of calls related to downed wires and electrical hazards in flooded basements. Thousands of Hydro Ottawa customers lost power, and some roads, including sections of Highway 417, were closed due to flooding. Mayor Mark Sutcliffe described the event as one of the worst flooding incidents in the city in the past 25 years.
While a tornado warning was briefly in effect for areas west of Cornwall on Thursday afternoon and subsequently lifted, the severe thunderstorm watch remains active. Authorities are urging residents to stay informed, monitor alerts from Environment Canada, and take immediate precautions if threatening weather approaches. This includes seeking shelter in basements or interior rooms away from windows, and exercising caution when driving due to potentially difficult conditions and the risk of flash flooding. The city is still cleaning up from Wednesday's deluge while preparing for the possibility of further severe weather.
