5-15cm of Snow for Southern and Eastern Ontario
More snow is approaching Ontario tonight. A deepening storm system with a center over the Ohio Valley and secondary development off the eastern seaboard of the US is advancing northeast. A wide area of snow will begin falling shortly in Windsor and spread north and east overnight. I believe the heaviest snow will stay south of Kemptville and The Seaway.
The heaviest snow at this time, over 15cm will fall from Windsor to Hamilton and south. North of there 5-10cm is expected from the GTA towards the Ottawa Valley. Winds along the north shore of Lake Erie will gust to 60km/h causing blowing snow and poor travel on the 401 tonight and Friday.

In the US, many areas of the northeast and southern New England are under Heavy Snow or Winter Storm Warnings. 15-30cm is expected in new York City and Boston. Further north snow advisories are in effect for most of central and southern New York and central New England.