What is "alberta clipper"

n. A snowstorm that travels quickly eastward from the Canadian Rockies.

An Alberta clipper (also known as a Canadian Clipper) is a fast moving low pressure area which generally affects the central provinces of Canada and parts of the Upper Midwest and Great Lakes regions of the United States, precipitating a sudden temperature drop and sharp winds. Alberta clippers take their name from Alberta, Canada, the province from which they appear to descend, and from clipper ships of the 19th century, one of the fastest ships of that time.