Several days of unseasonable heat and humidity culminated in some refreshing thunderstorms for parts of Ontario and Quebec on Saturday, even prompting warnings in spots. The storm threat will roll into Sunday as a cold front pushes through the provinces. Our week ahead looks to start with a quick cooldown. More on what you can expect in the days to come, below.
SUNDAY: STORMS SCOUR AWAY ONE LAST DAY OF HEAT
The unseasonable heat that’s bathed the eastern half of Canada over the past couple of days will be on borrowed time by Sunday.
A cold front pushing across the Great Lakes will slowly traverse southern sections of Ontario and Quebec through the day, providing both relief from the above-seasonal temperatures and a spark to trigger scattered thunderstorms.
There may be enough instability for a few of the storms to turn severe, mainly in southern Quebec. Any that do reach severe criteria could produce large hail and strong wind gusts.
Sunday’s temperature story will look similar to what we saw on Saturday across southern Ontario, though noticeably cooler in eastern sections and southern Quebec where temperatures in parts of the region will drop by seven or eight degrees. The humidity will remain in place, where feels-like values could be into the low 30s for southern and eastern Ontario, and approaching 30 in southern Quebec.
Temperatures will drop a few degrees below seasonal behind the cold front, putting an end to this early tease of summertime weather.
A quick round of rain will arrive across southern Ontario in time for the morning commute on Monday. The rain won’t prove to be a daylong event, but prepare for some slowdowns on Monday morning as commuters navigate wet roadways.
RISK OF FROST ACCOMPANIES BRIEF COOLDOWN, THEN WARMTH REBOUNDS
Temperatures falling on the cooler side of seasonal will make next week feel more like late-April than the middle of May. Daytime highs will register in the single and low double digits for most areas across the north, but mid-to-upper teens are still likely across the south.
Some higher elevations in southern Ontario will even need to watch out for frost during the mid-week mornings, as temperatures creep towards the freezing mark.
For those who couldn't get enough of the warmth, the signal is there late next week for temperatures to make a triumphant return into the upper 20s with another ridge taking shape.
Temperatures should rebound back to seasonal and possibly above seasonal for the start of the May long weekend that follows.
Be sure to check back for the latest weather updates across southern Ontario and Quebec.