Commuters in Hamilton should give themselves extra time getting to work and school Wednesday morning because of a burst of snow coming to Southern Ontario that will usher in blustery conditions and reduced visibility, Environment Canada says.

A low pressure system is expected to emerge from the southern U.S. Tuesday and spread snow into southwestern Ontario Tuesday night.

It is expected to reach Niagara and Toronto around midnight, and then communities north of Lake Ontario overnight.

Environment Canada issued a snowfall warning for the Hamilton area on Tuesday morning. Total amounts of 15 to 20 cm are likely in the Hamilton area with amounts in excess of 20 cm possible especially in the Niagara region before the snow tapers off later in the day.

The snow will fall heavily at times late Tuesday and into Wednesday morning due to local enhancement off of Lake Ontario.

"This will significantly impact the morning commute," Environment Canada says.

With files from The Canadian Press