Waterloo-Wellington and Huron-Perth are among a number of southern Ontario areas placed under a snowfall warning.

Environment Canada says heavy snow will blow into the area overnight, continuing to fall into Wednesday morning.

Precipitation began to fall Tuesday afternoon in Waterloo Region as rain, freezing rain and ice pellets. As temperatures dip Tuesday night, it is expected to turn into snow.

As much as five centimetres of snow per hour could accumulate during the heaviest part of the storm.

By noon Wednesday, Environment Canada expects 15 to 20 centimetres of snow on the ground in most of southern Ontario, with less along the Lake Ontario shoreline.

Drivers are warned that conditions will deteriorate quickly once the snow begins, with visibility less than 250 metres at the peak.

The City of Kitchener has declared a snow event, meaning any cars left on the road after 11:59 p.m. Tuesday may be ticketed or towed.

Kitchener city officials say a full fleet of 65 snowplows will be dispatched shortly after 2 a.m.

“We’ll be focusing on the regional road and main (streets) first, and we will likely not get into residential streets (until later,” said Jim Witmer, the city’s director of operations.

A snow event is also in place for the City of Waterloo. Cars there can’t park on the roads between 2:30 a.m. and 6 a.m. Wednesday.

Check Kitchener.ctvnews.ca and the Canada AM ticker Wednesday morning for up-to-date information on closures and cancellations.