Rain-showers or thunderstorms are expected to begin moving into deep Southwestern Ontario overnight Monday into Tuesday. Convection will spread throughout Southern Ontario throughout the morning and afternoon as a maturing-low approaches from the US. Another round is possible by the mid-evening along the shores of Lake Huron.
BRIEF CLEARING? & HEAVY RAINFALL
There may be some brief clearing stretching from the Golden Horseshoe into Southwestern Ontario. This would add more energy and instability, allowing for some isolated severe thunderstorms capable of very-strong winds and short-lived rotation.
Much of the day however, is expected to be dominated by cloud, showers and passing heavy thunderstorms – perhaps several rounds. This could lead to locally significant rainfall-totals. With the threat of localized flooding. Widespread amounts between 30-50mm is expected.
East of Georgian Bay stretching into East of Superior will see a beneficial, soaking rainfall from this system. Which will help alleviate forest fire concerns, plaguing the region this summer.
This will be an early fall-like system for the Great Lakes. As we move deeper into August we are beginning to enter a transitional period, where low-pressure systems produce synoptic rain and wind over a larger area. Widespread winds gusting between 50-70km/h are expected between Tuesday late-afternoon, and through the evening.
No need for “the end of sunmer blues” quite yet, temperatures by this weekend will be near 30c feeling closer to 40c with the humdity factored in.