What Are The Dry, Gusty Winds That Originate In The Eastern Rocky Mountains Of North America?

Chinook winds, a variety of Foehn winds, are warm, dry, gusty usually irregularly occurring winds that come down the lee slopes in the Eastern Rocky Mountains and come into the North American plains. These gusts occur from the movement of both high and low pressure systems, when precipitation causes the air to be stripped of its moisture. As it rises and cools it releases heat. With the wind's movement through and over the mountains, there is a condensation of moisture that falls as precipitation. This warms the air because of the release of latent heat. With the descent of the air on the mountain range's leeward side the air is made warm and dry by adiabatic compression. Warm air that descends the slope could displace a cold, moist air mass already in existence. This only enhances the rise in temperature and decrease in moisture that is associated with the Chinook. Night time temperatures can also remain high, because the normal pattern of nocturnal temperature inversion can be prevented from forming on the slope's lee side by the turbulence of the high winds.