Late-season warmth, rain and storm risk sneaks into southern Ontario
Southern Ontario will get a glimpse of late spring warmth Wednesday, with temperatures reaching the 20s in many locales, accompanied by the chance of some showery weather and the risk of thunderstorms.
While the northwestern sections of Ontario deal with the prolonged impacts of a major blizzard Wednesday, the south will be basking in late-season warmth, however brief. Temperatures will climb into the 20s, though those along the lakeshores of the Greater Toronto Area (GTA) may be held back because of the pesky east wind. But a price for the mild temperatures will be rain and possible thunderstorms, especially in the southwest where there's a conditional risk of storms reaching severe criteria. More on the incoming warmth and unsettled weather risks, below.
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While the eastern Prairies is set to be battered by a potentially historic blizzard that could bring with a widespread 30-50 cm of snow, with local amounts as high as 75 cm, the same system will effect southern Ontario Wednesday -- though it won't be nearly as impactful.
The warm front will move through southern Ontario Wednesday, bringing some warmer temperatures for southwestern portions but the system will only reach areas just east of Georgian Bay and through the central parts of the GTA, keeping eastern Ontario a bit colder than what is expected Tuesday.
A sharp temperature contrast will be felt across the south on Wednesday with widespread lower 20s as daytime highs -- with a few spots possibly reaching the mid-20s -- for areas west of the GTA. A very tricky forecast for the GTA, however, as there is uncertainty as to whether the east wind will hold and keep temperatures rather chilly or if the warmer weather can advance into western parts of the region. Temperatures will remain near to below seasonal to the north and east of Toronto.
Early Wednesday morning will see rain and rumbles of thunder push through areas near Georgian Bay and Lake Huron. Rainfall warnings are in place, extending into Parry Sound-Muskoka and Algonquin regions. Total rainfall amounts could range between 30-50 mm, particularly in regions that experience thunderstorms.
As well, on Wednesday, there is also the risk for some thunderstorms throughout the day. As the warm front lifts north across southern Ontario, rain and isolated thunderstorms will be possible along the front.
Through the afternoon, with enough sunshine and daytime heating building instability, a few scattered storms may also develop in parts of southern Ontario. Southwestern sections may see severe storms develop with the aid of lake breezes along the Lake Erie shores, depending on the timing of the cold front. The risk is very conditional.
The main threats will be heavy rain and strong winds, with the chance of small hail, too.
As we head through the early morning hours of Thursday, the cold front will slice through southern Ontario bringing some more rain and possible rumbles of thunder along with cool, blustery west winds behind the front. Temperatures will still be rather mild behind the front with sunshine spreading across southern Ontario for the afternoon.
However, temperatures in southwestern Ontario and towards the Huron shores will be about 10 degrees cooler from the previous day.
As for Easter weekend, another cold front will send temperatures diving to well below seasonal values, including on the holiday itself.
A blocking pattern will keep the chilly pattern across the region through next week. Closely watching to see if parts of the region will see some significant snow to go along with the cold temperatures.
Thumbnail courtesy of Lisa Witherspoon, taken in Willow Beach, Ont.
Stay tuned to The Weather Network for the latest forecast updates on southern Ontario.