Rain changes to snow today in Montreal

Expect snow covered roads in Montreal by late today as temperatures drop below freezing.

Up to 5cm of snow is possible this afternoon into this evening across eastern Ontario and the St. Lawrence Valley. Rain will mix with and change to snow by 1pm in Montreal. Roads will become slippery as temperatures drop well-below freezing by the evening hours.

When I first started writing about the weather around the age of 10 or so, I would issue a first snow alert to my family and friends. The idea was that the snow, while not really a storm, was the first of the season, and would bring along with it the usual problems on the roads. So consider this your "first snow alert."

Our first measurable snow of the young season is on our doorstep this Friday morning. Weakening low pressure will move from the Great Lakes into New England, while a second area of low pressure develops and moves into Maine. A strong cold front will sweep across southern Quebec by the noon hour, bringing in the coldest air so far this fall.

Rain is currently falling in advance of the cold front. The rain will mix with and change to snow in the Ottawa Valley this morning and gradually across our region from west to east this afternoon. Expect 2-5cm for metro Montreal, with 10-20cm across the highest elevations of the Eastern Townships.

On the US side of the border, heavy snow is expected in the Adirondacks and Green Mountains, where winter storm warnings have been posted. Over 30cm is possible at the highest elevations. This will be an elevation dependent storm so from the valley floors up, amounts will increase.

Once the snow ends in Montreal tonight, the weather will turn blustery and cold. Expect northwest winds of 30-50km/h combined with a forecast low of -5C (23F), to produce windchills in the minus teens. Saturday will be cloudy, blustery and cold, with flurries and a high of only -4C (25F).

The sun will return on Sunday, but temperatures will remain chilly, with a high of -2C (29F).