Sudden whiteout conditions and "bursts of heavy snow" are possible for Windsor-Essex and Chatham-Kent Tuesday, says Environment Canada.
The weather authority issued a snow squall watch for the area warning visibility will be reduced because of heavy snow and strong winds.
"The snow squalls may extend quite far inland at times tonight, likely crossing Highway 402 and possibly extending across Highway 401 in Chatham-Kent," cautioned the watch that was posted just before 5 a.m.
Environment Canada also predicted up to 15 cm of snowfall could quickly accumulate and road closures are possible.
Weather causes collisions, flight cancellations
The threatening conditions have prompted several cancellations at Detroit Metropolitan Airport and at least one at Windsor Airport, the 9:55 a.m. to Toronto.
About 10 centimetres of snow fell in Essex County over the past 24 hours, Environment Canada said Tuesday morning. That fell short of the "major winter storm" initially forecast but it still caused havoc on area roadways.
There were multiple collisions in the city and county Monday, including an afternoon crash in Kingsville that sent a four-year-old boy and his father to hospital.
LaSalle Fire Service dealt with at least six injury accidents Monday afternoon and urged motorists to slow down in snowy conditions.