Saturday, April 10th 2021, 9:38 am - Enjoy the start to this early summer-like weekend before a major pattern shift sees much cooler temperatures coming to round out April in Ontario.
Southern Ontario will get a taste of early summer to kick-start the weekend, with well above seasonal temperatures that will hit the low and even mid-20s in parts of the region, away from the lakeshores. This is all thanks to a mild, southerly flow. However, enjoy the pleasant weather while you can because a Texas low is on the doorsteps and will push rain into the southwest first Saturday evening. A gradual, but major shift in the pattern will begin next week, with much cooler weather expected into the second half of April. More on the timing, below.
SATURDAY: FEELING LIKE EARLY JUNE AS TEMPERATURES SOAR
Southern Ontario can expect a great start to the weekend, featuring plenty of sunshine and well above seasonal temperatures. In fact, they will be early summer-like.
Temperatures across the region are likely to reach low- to mid-20s in the afternoon. A mild, southerly flow will allow southern Ontario to tap into yet another early summer airmass.
Enjoy the weather while you can, though, because active weather brewing stateside will eventually push into the southwest in the evening hours, continuing overnight.
SUNDAY: RAIN WILL MOVE OUT QUICKLY, DRY BREAKS IN AFTERNOON
Moisture from the Texas low will allow for periods of rain to continue into early Sunday morning in the south. Showers will likely reach the GTA by pre-dawn hours Sunday morning, but will be fairly quick to push out. Dry breaks are expected by late-afternoon for parts of southern Ontario.
Rainfall amounts will be heaviest in a narrow swath extending from southern Georgian Bay to parts of the Golden Horseshoe. This area can expect to see 20-30 mm of rainfall through Sunday. 10-20 mm for areas just east and west of the aforementioned regions, and lesser amounts in most of the southwest and cottage country.
MAJOR SHIFT IN THE PATTERN AS TEMPERATURES BECOME COOLER NEXT WEEK
There will be a major, but slow, shift in the weather pattern for next week, one that looks to bring much cooler conditions to Ontario, thanks to a deep trough in the jet stream that is expected to develop over Ontario.
"The third week of April looks rather chilly, which will be quite an unpleasant and disappointing contrast to what we have enjoyed so far this spring," says Gillham. "Colder than seasonal temperatures are expected as we head into the second half of April."
The chilly pattern is expected to continue into the fourth week of April, as well.
Check back as we continue to monitor the latest forecast in Ontario.