A Chinook wind is a weather phenomenon that creates warm, dry air that blows down the eastern slopes of the Canadian Rockies. The name Chinook means "snow eater," as the wind occurs most frequently in winter and can disrupt snowstorms and melt fallen snow.
When warm, moist air from the Pacific rises over the mountains in western Canada, it cools, and the moisture condenses out of the air. As the dry air descends over the eastern slopes, it picks up speed and warms significantly, creating the distinct Chinook wind signature. The winds can reach hurricane force and raise temperatures in the affected area by up to 40 degrees in a single hour.