Environment Canada has issued a warning to residents of London to prepare for a significant thunderstorm expected to pass through the area on Wednesday afternoon. Severe weather meteorologist Rob Kuhn stated that the storm’s peak risk period is between 4 p.m. and 8 p.m., with the potential for heavy rainfall of up to 60mm, hail ranging from three to five centimetres, and wind gusts reaching speeds as high as 130km/h.
Kuhn emphasized the potential impact of the thunderstorms, highlighting the risk of isolated tornadoes developing later in the day. This weather event coincides with an extreme heat advisory for London, with temperatures expected to reach 32°C and a humidex making it feel closer to 41. The weather agency issued a yellow heat alert for the area on Tuesday, which may extend into Thursday.
Attributing the storm system to lower Michigan, Kuhn noted that the existing hot and humid air mass from the United States has moved into southwestern Ontario. He expressed concerns that the thunderstorms could escalate in intensity as they approach London.
A yellow weather alert indicates increased health and activity risks, especially for individuals sensitive to extreme heat. The Middlesex-London Health Unit (MLHU) advised community members to take necessary precautions, stay hydrated, minimize outdoor exposure, seek shade, and avoid strenuous activities. Additionally, they warned against leaving children or pets in parked vehicles.
As the storm passes, overnight temperatures are expected to drop to 19°C with limited relief. Weather conditions are predicted to stabilize quickly following the storm. Thursday’s forecast includes mainly cloudy skies, a 40 percent chance of late afternoon showers, a potential thunderstorm, and a high of 27°C, feeling like 35. Friday and Saturday are expected to be cloudy with chances of showers, reaching highs of 26°C and 24°C, respectively.