Widespread frost expected across southern Quebec

Fast moving late season thunderstorms swept across the Island of Montreal and Laval on Wednesday, October 7. Some of the storms produced heavy rain and minor flooding as shown above on Eliot Avenue in Chomedey. (T. Giotsalitis) 

If the growing season has not yet ended in your community, it likely will overnight into Friday morning. Frost warnings are in effect for metro Montreal, with freezing temperatures forecast across the region.

A cold front swept across southern Quebec late Wednesday, accompanied by a round of potent showers and isolated thunderstorms. Some regions, including parts of Laval received quite a decent downpour, with some isolated flooding reported. Officially only 8mm fell at Trudeau Airport in Dorval. A wind gust to 74km/h was also reported with the storms at Trudeau.

Behind the front, much cooler air settled into Montreal, but gusty winds managed to keep the temperatures above the freezing point Wednesday night. It has been a chilly day in Montreal, with the high so far only reaching 10C (50F), accompanied by 50km/h northwest winds. As winds diminish this evening and skies clear out, a general frost is expected. Overnight lows will range from 0C (32F) in the city to -2C (28F) in the suburbs. Friday will be sunny and a touch warmer, with a high in the low teens. 

On Saturday, another warm front will lift across the St. Lawrence Valley, with a repeat of Wednesday's weather expected. The day will be breezy and warm, with a high of 21C (70F) before a cold front arrives in the late afternoon. The front will be accompanied by heavy showers and perhaps a rumble or two of thunder. Temperatures will quickly fall back once again into the single digits and only rise to 11C (52F) on Sunday.