Environment Canada has ended a snow squall watch for London, eastern Middlesex County and Oxford County.
Forecasters say northwest winds blowing over the relatively warm waters of Lake Huron are generating lines of flurries and snow squalls that are expected to sweep into the area Friday.
The weather agency says the heaviest squalls could produce a snowfall rate of 10-15cm per 12 hours.
Forecasters are also warning of reduced visibility when the flurries and squalls hit. They say weather conditions throughout the region can vary, with clear skies in one spot and whiteouts just a few kilometres away.
Provincial police say motorists will need to adjust their driving to meet the conditions.