Cooler temperatures will dominate through the end of this week in Ontario due to frigid air aloft associated with an upper level trough. This means that temperatures could become below-seasonal, which will linger into the weekend. Scattered showers will impact southern regions of the province while northern areas are seeing the potential for snow. Details and timing, below.
- Showers, thunderstorm risk throughout most Ontario on Thursday
- Elevated chance of waterspouts in Lake Huron and Lake Erie
- Cooler air late week, triggering snow in the north
WEDNESDAY STORMS BROUGHT HAIL, HEAVY RAIN
Pea-sized to dime-sized hail fell in parts of southern Ontario on Wednesday evening as thunderstorms and heavy rain tracked through.
THURSDAY AND BEYOND: FALL TEMPERATURES IN THE SOUTH, SNOW IN THE NORTH
Scattered showers and lake-effect rain will continue in southern Ontario throughout the day. There is even the potential for non-severe thunderstorms due to cool, unstable air in the upper levels of the atmosphere.
The elevated risk of waterspouts for Lakes Huron and Erie continues through Thursday. Though atmospheric temperatures will be cooler than in recent days, the lakes take longer to lose their warmth. This creates a relatively high chance of convection coupled with winds that may spark rotation beneath cumulus clouds.
Though impressive and ominous to look at from the shore, they are largely harmless, though occasionally one will come onto land as a weak landspout tornado.
Temperatures will be near or slightly-below seasonal for southern Ontario, which is quite the contrast from the temperatures in the mid-twenties that we saw at the beginning of the week. This cooler temperature trend will continue through the weekend and several northern regions could soon see snowfall.
For most people, it’ll be no more than short-lived “conversational” snow, and not at all out of the ordinary for early October, but still a reminder that summer is definitely over.