What is the technical explanation for a chinook?

Question

What is the technical explanation for a chinook?

Answer 1

Chinook is a local name for a foehn. As air sweeps over a mountain range, it cools to the point at which it cannot maintain its moisture and the windward side of the mountain receives rain or snow, When the air, drier now, descends on the leeward side of the mountain, it warms up. Because it is drier, it gains heat faster than it lost the heat  while it rose. The result is a warm wind on the leeward side of the mountains. As I recall, the record is on the order of a 60°F rise in temperature during a couple of hours when a chinook hit. If you don't like the weather, wait five minutes ;-)

Answer 2

A Chin What.

Answer 3

I thought it was a type of helicopter?

Answer 4

A chinook is a wind most notable in the northern high plains that brings in drier and warmer weather.

One of the main reasons for the change in the weather is the sloped elevation. When air moves from the higher elevations of the west it downslopes as it moves east. Since the air is downsloping the temperature and relative humidity of the air will change adiabatically. Sinking air warms at the dry adiabatic lapse rate. When this warmer air replaces a very cold polar air mass the temperature increase can be dramatic.

Another name for the chinook is "snow eater" since the warm and dry air quickly melts and evaporates snow away that is on the ground. The air at the high elevations tends to be dry (low dewpoint). When air downslopes it dries the air even more since the relative humidity decreases. As the temperature of air warms as it downslopes the temperature and dewpoint diverge (dewpoint depression becomes greater). As the dewpoint depression increases the relative humidity decreases.

The chinook is most notable in the winter in the northern high plains.