Heavy rain...then snow

We have a very active and complex weather weekend underway. It will start with heavy rain and mild temperatures and end with heavy wet snow and strong winds along with dropping temperatures. For today a Heavy Rain Warning is posted for all of southern Quebec and Ontario. Between 30-50mm of rain will fall along the 401 corridor and into southern Quebec in the next 12-18 hours. On Sunday the rain will change to snow from west to east starting in eastern Ontario early in the morning and spreading south and east. Temperatures today will reach a very mild plus 7C and remain there overnight before rapidly dropping on Sunday to -4C by late in the day. The rain will change to wet snow with 10-15cm easily accumulating in southern Quebec with lesser amounts in Ontario. The culprit is a very slow moving frontal boundary across the Great Lakes along with developing low pressure along the eastern seaboard. Roads will become very slippery on Sunday along with increasing north winds and blowing snow. The snow will only end on Monday. Already Winter Storm Watches are posted in New York and Vermont for this event. We may see additional warnings for Montreal and Quebec once the rainfall warning expires later tonight. I would avoid any travelling on Sunday if possible, especially outside the city.