Environment Canada has issued a snow squall warning for Waterloo Region Monday evening.
There will be local blowing snow, and between 15 to 20 cm of snow this evening and possibly into Tuesday morning.
Meanwhile, Guelph and parts of Wellington County are still under a snow squall watch, which means the squalls are likely.
The weather service warns that the squalls could be intense in small areas, and visibility could be drastically reduced for a short time in the squall zone.
"The snow squalls are forecast to be vigorous, with associated snowfall rates of several centimetres per hour possible under the stronger bands. Additionally, strong and gusty northwest winds may carry the snow squalls well inland, and also result in areas of blowing snow," the weather service says.
If the squall system stalls in an area for longer than expected, snowfall accumulation could be large.
"To the lee of Lake Huron, most likely in a swath from south of Kincardine to about Listowel, snowfall accumulation could reach 40 or 50 cm. To the southwest of Georgian Bay, from about Wasaga Beach to near Innisfil, up to 30 cm in total are possible," the weather agency advises.
The periodic squalls could persist into Tuesday, Environment Canada said.