Parts of Simcoe County are under a snow squall warning on Thursday, that Environment Canada forecasts will remain in place through to Friday.
The weather agency states, "Local snowfall accumulations of 20 to 30 cm will be possible under the most intense bands by Friday morning."
"Drivers are going too fast for these conditions," said OPP Sgt. Kerry Schmidt.
The wintry weather may have been a factor in a serious crash on Highway 400 on Thursday morning that forced the closure of the northbound lanes in King Township.
A tractor-trailer and vehicle collided around 7:30 a.m. between King and Aurora roads.
A car crashes into a ditch north of King Township on Highway 400 following a two-vehicle collision on Thurs., Nov. 7, 2019.
"One of the vehicles flipped over several times as well. That driver has serious injuries, not appears to be life-threatening," Sgt. Schmidt said.
The driver was taken to hospital. No word on any charges or the exact cause of the crash.
