|The European forecast model of accumulated precipitation through Sunday for eastern North America; Montreal and southern Quebec are looking at the potential for 100mm of rain. (AccuWeather - click to make map larger)|
Heavy rain is forecast in Montreal over the next 48 hours, as strong low pressure moves from the Ohio Valley into southern Quebec this weekend. Rain is forecast to develop by mid-day Thursday and become heavy at times into the overnight hours. The rain will persist throughout Friday. At this time, computer models are indicating 50 to 100mm (2 to 4 inches) of rain for our region. Strong winds will also develop on Friday, as the storm system pulls off to our north and east. The wind will accelerate leaves falling off the trees making driving slick and clogging drains and sewers.
In addition to the increase in wind, temperatures will begin to drop. High temperatures will be near 14C (56F) today, but lower to only the single digits by late Saturday and Sunday. There is even the chance of some wet snow in both Ottawa and Montreal by late Saturday night or early Sunday. No accumulations are expected in the valley. Snow may, however, accumulate several centimetres well north of Montreal, as well as across the mountains of the Eastern Townships and northern New England. The cool, damp weather will persist into early next week.
If that was not enough, forecasters are watching an area of disturbed weather northeast of the Bahamas on Thursday morning. The system has the potential to develop into a tropical or sub-tropical storm over the next 48 hours. If it does develop, it would be named Otto. In any event, this system will pump Atlantic moisture into the northern storm, enhancing the rainfall across portions of Quebec and Atlantic Canada by late in the weekend.