ONTARIO: Thunderstorm Forecast for Wednesday, July 26, 2023

/

NOTE: YOU CAN CLICK ON THE MAP TO OPEN A ZOOMABLE IMAGE WHICH WILL BE EASIER TO READ.

FORECAST DISCUSSION

Wednesday is shaping to be a potentially active day as indications point towards a strong severe risk across Southwestern Ontario during the late afternoon and evening hours. A potent environment is expected to develop, creating favourable conditions for severe weather.

Current models are suggesting the formation of a line of intense thunderstorms during the afternoon over Lower Michigan, which will track toward Southwestern Ontario by the evening. Unfortunately, this echoes last week's significant severe weather event, and areas hardest hit then are currently at the highest risk again. The exact timing of these storms will play a crucial role in the overall severe threat on our side of the border.

Presently, we are leaning towards a strong severe risk, stretching along the Lake Huron shoreline and southward into London, Sarnia, Chatham, and Windsor. As we gain more clarity on timing, the likelihood of introducing a 'significant' severe risk in this area is quite high. The severe threat could carry as far east as the GTA and Niagara region although that is questionable.

⚠️ Potential Threats

  • Destructive Wind Gusts: Expect the potential for widespread wind damage.

  • Very Large Hail: Hailstones of considerable size may cause damage to property and vehicles.

  • Flash Flooding: A major concern with localized rainfall totals of 100-150mm possible in a few hours.

  • Tornadoes: While uncertain, the environment may support a few tornadoes which is highly dependent on timing.

🕓 Timing

  • Southwestern Ontario: 6 - 10 PM

  • GTHA/Niagara: 8 PM - 12 AM

NOTE: This is a preliminary forecast and could change as we get closer to Wednesday. The forecast should only serve as a rough idea of potential threats and timing.