|A messy mix of snow and freezing rain is expected for Montreal and Ottawa this weekend. (AccuWeather)|
A very active weather weekend is forecast, as low pressure develops over Colorado and moves northeast towards Quebec and Ontario. A warm front in advance of the storm will approach the St. Lawrence Valley late Saturday. Clouds are expected to increase this afternoon, followed by light snow by midnight tonight. The light snow will persist into Saturday with 5 to 10cm (2 to 4 inches) expected in Montreal. By late Saturday, enough warm air will arrive to change the snow to a messy mix in the St. Lawrence Valley. Freezing rain is likely, creating icy travel into Sunday morning. Some plain rain is even possible south of Montreal into New York and Vermont. On Sunday, another arctic cold front will arrive by midday, freezing up all the precipitation that has fallen. The temperature is expected to fall from the forecast high of 2C (36F) Sunday, down to -20C (-4F) by Monday morning.
Travel will be impacted. As a result, a Winter Storm Watch is in effect for our eastern Ontario neighbours, with winter-weather advisories in New England. A special weather statement is covering this mess for southern Quebec, but warnings may be posted later today. A storm with a rain and snow mix is possible by Christmas Eve.