Wind gusts of up to 60 km/h are also expected, which may result in widespread blowing snow.
Blowing snow with an accumulation of as much as six centimetres by Monday night is being forecast for Sarnia-Lambton by Environment Canada. "The biggest impacts at this point will be in the western part of the GTA and we still do have winter storm warnings in effect in areas from Hamilton down into the Niagara Peninsula".
More winter storm watches and warnings will likely be released as the weather system that is now blowing our way from the northwestern United States draws closer, Environment Canada said.
Snow is forecast to begin during the day Monday and keep falling into early Wednesday as the storm moves to Eastern Ontario.
Knott predicts the snow will continue until Wednesday morning. Total snowfall amounts of 10 to 20 cm are expected by Wednesday. Unsafe driving conditions are expected to last until Tuesday evening.
Travel conditions, warns Environment Canada, may become hazardous.
The Greater Toronto area is bracing for up to 15 centimetres of snow by Tuesday night, with the Hamilton area set to receive upwards of 25 centimetres. The wind chill Tuesday morning is expected to be -28 C.
"There may be significant impact on rush hour traffic in urban areas".
Get ready to feel winter's wrath, Toronto.