Possible Severe Thunderstorms on Sunday to End Off a Stretch of Summer-Like Weather Across Southern Ontario This Week

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

As the saying goes, 'All good things must come to an end,' and that will become apparent on Sunday as we cap off what has been a stellar week when it comes to the weather. We saw temperatures well into the 20s for multiple days this weekend, which is rare in April. A cold front is expected to slide across the region during the afternoon and evening on Sunday, ushering in much colder air. In addition to providing a sharp drop in temperatures, the front will also spark off another common summer weather phenomenon - thunderstorms!

A line of rain is expected to develop ahead of the front and track across Southwestern Ontario and into the Golden Horseshoe starting just after the lunch hour and continuing throughout the evening. This line will likely have embedded thunderstorms which should remain non-severe for the most part. However, the environment is strong enough to allow an isolated storm to briefly become severe, with the main threat being 90km/h wind gusts and up to pea-sized hail.

The risk zone for the isolated storm includes all of Deep Southwestern Ontario and into the Hamilton/Niagara region. Remember, this is only an isolated risk, and any strong storms will be very localized. Not everyone will see a severe storm tomorrow. Outside of the severe threat, non-severe thunderstorms could deliver heavy rainfall and frequent lightning strikes across much of Southern Ontario. Eastern Ontario could see a few lightning strikes later overnight and pre-dawn Monday, but we didn't include them in the map as this is for Sunday only.

We will continue to monitor the latest data and may update this forecast by early Sunday afternoon if needed. Stay safe!