Environment Canada has a winter weather travel advisory from Kingston to Ottawa-Gatineau to Hawkesbury Tuesday.
The federal weather agency said overnight rain would change to to heavy snowfall Tuesday morning.
In all, from five to 10 centimetres of snow is expected to fall, at times falling at a rate of three centimetres per hour.
The higher end of that would challenge Ottawa's April 19 snow record of 10.6 cm recorded around the Central Experimental Farm in 1904.
With temperatures forecasted to stay above 0 C, that snow may not all stick. It's expected to limit visibility for commuters along with the slick roads.
Precipitation may fall as a mix of rain and snow in the afternoon before more snow from sunset to midnight in Ottawa. There's more of a chance of flurries Tuesday night closer to Kingston.
Highs Wednesday are expected to be around 10 C and stay below the seasonal average high (13 C in Ottawa) until Friday.
Areas not covered by the advisory should see a mix of rain and snow Tuesday, but with less snow.