According to The Weather Network, a "classic" fall storm with rain, gusting winds, a temperature drop and snowflakes is expected from Thursday, October 15 to Saturday, October 17.
The forecast has called for a blast of Arctic air that could turn rain showers into a wintry mix and bring the first lake-effect snow of the season to southern Ontario.
A low-pressure system is expected to move through the province on Thursday evening, which means it will be rainy and windy in most of Ontario, with 10 to 30 millimetres expected in southern and central parts of the province.
The Weather Network said rainfall will continue overnight into Friday between Toronto and Ottawa and taper off by the morning, but scattered showers are possible throughout the day.
Then, colder air from the north will surge into the province after the low-pressure system moves out. A "rapid drop" in temperatures and northerly wind gusts around 50 kilometres per hour are forecast on Friday evening.
Some parts of the province could have temperatures near or below 0 C on Friday evening, with the wind chill making it even colder overnight.
The Weather Network said colder air over the relatively warm waters of the Great Lakes could cause lake-effect precipitation and bands of showers downwind of Lake Huron and Georgian Bay.
As temperatures drop, some of the precipitation could turn into snow on Friday evening and overnight into Saturday.
While there is uncertainty about the mixed precipitation and how much of it southern Ontario will get, parts of cottage country and places south and east of Lake Huron and Georgian Bay could get the first snow of the season this weekend.
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