Snow squalls are expected to develop Thursday and intensify Thursday night into Friday.
Snow squall warnings were posted Thursday morning for north and east Lambton County, as well as Middlesex County, Huron-Perth, Grey-Bruce, Dufferin-Innisfil, and Barrie-Orillia.
Environment Canada said snow squalls will develop off southern Lake Huron and Georgian Bay Thursday as northwest winds pick up. Total snowfall amounts of 30 centimetres to 40 centimetres, over a foot, are possible in the heaviest bands of snow Thursday night into Friday.
Meteorologist Gerald Cheng said he expects accumulations in north and east Lambton will be at the lower end.
"Especially along the lake, that's where the highest accumulations will occur," said Cheng. "As you move away from the lake, that's when accumulations sort of die down, but still we expect some accumulations in the area."
The snow squalls are forecasted to weaken by Friday evening as winds diminish.
Cheng said quickly changing conditions will result in reduced visibility at times, and it will be unseasonably cold for the foreseeable future.
"We are under this very cold air mass, our daytime highs should be about nine degrees and if you check the forecast we're nowhere near that. Even heading into the weekend temperatures will be three or four degrees, so it's time to bundle up and get used to these temperatures," he said.
A wind chill of -10 C (14 F) is forecasted for Thursday night into Friday morning.