Potentially heavy bands of snow are expected to develop off Lake Huron in the wake of a fast-moving Alberta clipper Monday night.
Environment Canada issued a snow squall warning Tuesday morning for Watford, Pinery Park and eastern Lambton County, as well as London-Middlesex and Huron County.
The weather agency says snow squalls will be ushered in from Lake Huron by strong and gusty northwest winds beginning Tuesday morning and continuing into Wednesday.
Snow amounts near 15 cm per 12 hours are likely in the strongest snow squalls and there is the potential for lake effect snow bands to become stationary for several hours at a time Tuesday afternoon into Wednesday. If that happens, local snowfall amounts of 30 cm (12 inch) or more are quite possible in the region, including the city of London.
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. Road closures are possible and it's recommended motorists consider postponing non-essential travel until conditions improve.
The Alberta Clipper will sail across southern Ontario Monday night into Tuesday morning bringing a general snowfall of 5 cm to 10 cm (2 to 4 inch).
Localized amounts of 10 cm to 15 cm are possible in some areas.