An Alberta Clipper is the name for an area of low pressure that forms over Alberta, Canada. This fast moving storm was named during colonial times when clippers, small ships, were the fastest moving vehicles.
The storm first develops when warm, moist winds from the Pacific interact with the mountains of British Columbia. As this air flows down the leeward side of the mountain into Alberta, a chinook forms.
The warmer air from the chinook mixes with the cold air mass across the region forming a strong area of low pressure.
The area of low pressure gets caught up in the flow of the polar high sending it southeast to towards the northern plains and upper midwest. Alberta Clippers can impact areas from the Dakotas down to Ohio.
With its arrival temperatures can plunge as much as 30 degrees in as little as 12 hours. The brisk winds up to 35 to 45 mph add to the chilling effect.
Snowfall is normally light 1 to 3 inches with a clipper unless it taps into another moisture source, like the Gulf of Mexico, and then you could see up to 8 inches.
Snowfall totals can be higher when clippers cross the Great Lakes. They enhance lake effect snow.
Clippers can occasionally produce heavy snow across the northeast and southeast Canada. This occurs when the clipper dives farther south than normal crossing the Applalachians.
The low feeds on the warm, moist air from the Atlantic and grows into a nor'easter. The New England Blizzard of '78 originated from a clipper that developed into a nor'easter on Feb. 5, 1978. It dumped up to 55 inches of snow in some locations.
Alberta Clippers normally occur during the months of December through February. However, they can appear as early as November.
The Manitoba Maulers and the Saskatchewan Screamers are two other types of clippers. They are less common than the Alberta, and are named for the Canadian province that they originate from.