CHINOOK, the name given to a wind which blows from west or north over the Rocky Mountains, where it descends as a dry wind, warm in winter and cool in summer. It is due to a cyclone passing northward, and continues for a few hours to several days. It moderates the climate of the eastern Rockies, the snow melting quickly on account of its warmth and vanishing on ac count of its dryness, so that it is said to "lick up" the snow from the slopes.