Chinook wind
Chinook winds are a wind pattern observed in midwestern North America, named for the Chinook Indians. Chinook winds have been observed to elevate midwestern winter temperatures, often below -20 C (-4 F) to as high as 10-20 C (50-68 C), for a short period of time, at the end of which, the temperatures plummet to their base levels.
The Chinook phenomenon results from the movement of high and low pressure systems over the Rocky Mountains. As the wind moves over and through the mountains, the moisture in the air condenses but, as it moves downhill, the cold air above presses down upon it. This results in adiabatic compression, the result of which is heat.
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