You maybe interested to know that 'Chinook' is a American Indian name, meaning 'Snow Eater'. Obviously this name comes from exactly what it does.
The temperature difference between one side of the mountain and the other can be a as much as 20C!!!
Lufftwaffle has got it right!!!
RatherBeFlying... Katabatic winds are not really related to this phenomenon.
Katabatic Winds is the flow of air at night down a mountain. This occurs typically when a snow covered mountain side cools a 2 meter layer of air. This cooled layer is colder than the surrounding air, so it starts sinking and proceeds down the mountain side. Thus creating the Katabatic winds!!!