First frost in Montreal followed by a return to warmer weather

A record breaking 38cm of snow fell on Calgary this week, with as much as 60cm near Kananaskis. It was the largest October snowfall in 124 years of record keeping for the city. (CTV News)

The temperature in Montreal is set to fall rapidly late this afternoon and evening as a cold front has cleared southern Quebec. The mercury soared to 24.4C (76F) in Montreal Thursday afternoon, the warmest in the country, but expect it to fall just as quickly after sunset tonight. The wind will soon back to the northwest and gust to 50km/h this evening, ushering in the colder air.

Environment Canada has issued frost advisories across eastern Ontario and southern Quebec, with many areas expecting there first sub-zero temperatures of the season. The majority of the frost is expected away from metro regions and bodies of water. Friday will be sunny, crisp and cool, with a daytime high near 12C (54F). On the weekend, we can expect a repeat of the recent cycle of weather events, with sunny skies and warmer temperatures Saturday, followed by rainy, mild weather Sunday and Thanksgiving Monday. High temperatures will be 14C (56F) Saturday, but into the high teens and low 20s Sunday and next week.

More snow west, warmth east
The central part of the country is expected to become the battle line between winter conditions in the west, and warmer, summery weather in the east. Calgary measured 32.8cm of snow on October 2, the snowiest October day dating back to 1884. The previous record of 29.7cm was set on October 4, 1914, The unprecedented storm closed highways, delayed flights at airports and caused hundreds of accidents. Calgary has received help clearing the snow from Red Dear and Edmonton. Lighter snow stretched east into Saskatchewan and Manitoba. Northwest Ontario was the dividing line, with heavy rain and strong winds occurring there. The early onset of winter is expected to continue next week, with more cold weather and snow expected from Alberta to Manitoba. Another powerful storm is forecast to develop early next week in the southern Rockies, potentially spreading blizzard conditions into the northern plains and southern Prairies.

East of the storm track across southern Ontario and Quebec, more windy and warm weather is expected. Beyond next week, cooler weather may return to eastern Canada for the balance of October. While it will not be as cold as in western Canada, the temperature should return closer to normal values by late next week, or even slightly below. The normal high/low for Montreal this week should be 15C (59F) and 5C (41F) respectively.