A three day historic September snowstorm is winding down early Monday morning across southern Alberta and southwest Saskatchewan. The storm dumped huge amounts of wet snow across the region, with close to 100cm (40 inches) in Waterton Park, Alberta. Lethbridge recorded 45 to 55cm, with 31cm in Calgary. On Sunday alone, 24.6cm of snow fell in Calgary, breaking the single day September record of 22.9cm established on September 19, 1895. The storm responsible for the snow was packed with Pacific moisture, moving inland across Idaho and into Montana.
Across the border in northwest Montana, even more snow fell, with an unbelievable 122cm (48 inches) at Browning, Montana. Brownings average annual snowfall is 151cm (59.5"), and we are not even out of September! The storm produced the usual mid-winter problems, with major travel delays and power outages reported. Numerous trees fell under the wight of the heavy snow. Many schools were closed on Monday in southern Alberta and northwest Montana.
Snow also fell across southwest Saskatchewan on Sunday, with accumulations in the 15 to 25cm range forecast from Moose Jaw and Swift Current south towards the US border. It is common for snow to fall on the edges of the seasons in Saskatchewan, but the amount, intensity and duration experienced with this storm are rare. When I lived in southern Saskatchewan between 1997 and 2000, the two biggest snowstorms I encountered were during the months of October and May.
Warm weather in the east
While the snow was swirling across the west, warm and humid air surged into eastern North America. Dozens of records highs were set across the eastern US, with highs pushing into the middle 30s (90s) in many locations. Temperatures were quite warm in southern Ontario over the weekend, but slightly cooler here in southern Quebec. The weather in Montreal for the start of October will be quite unsettled. Showers and thunderstorms are likely Tuesday, along with mild high temperatures in the low 20s. By the end of the week, much cooler arrives on gusty northwest winds, with highs by Friday and Saturday only in the low teens.