Lake effect snow squalls are expected to dump up to 15 centimetres of snow across Sarnia and west Lambton.
Environment Canada posted a snow squall warning for the region.
Warning Preparedness Meteorologist Peter Kimbell said higher snowfall amounts are likely in north and east Lambton.
"In eastern Lambton county it will last much longer," said Kimbell. "It will begin late Friday afternoon or evening and last through until Sunday with 20 to 30 cm of snowfall. So, much more snow for eastern Lambton county and obviously, to that degree, worse driving conditions."
The national weather agency said peak snowfall rates exceeding five centimetres an hour are possible Friday afternoon into the evening hours.
Visibility may be suddenly reduced at times in heavy snow.
Surfaces such as highways, roads, walkways and parking lots may become difficult to navigate due to accumulating snow.
The weather agency is advising motorists to consider postponing non-essential travel until conditions improve.
If you must travel, keep others informed of your schedule and destination and carry an emergency kit and mobile phone.
With files from Melanie Irwin and Natalia Vega