What are Chinook winds?
Chinook winds blow in from the Pacific in late winter and early spring. Their moisture evaporates as they pass over the Rocky Mountains. Once the winds come down from the mountains onto the high plains, the air can be quite mild and extremely dry,. When a Chinook takes effect local temperatures can warm up from as low as 5 degrees below zero to 60 or 70 degrees Fahrenheit. The air is so dry that when it hits snow, it sucks up the moisture, changing the snow directly into water vapor, bypassing the liquid phasethat slushy phase– entirely. Called sublimation, this is a common way for snow to disappear quickly in arid climates.
A Chinook wind is a dry warm to hot wind that flows down the leeward (eastern) side of the Rocky Mountains. It is a type of katabatic wind. The Chinook wind is caused by pacific winds climbing the windward (western) Rocky Mountains and loosing moisture and temperature as it climbs. This brings moisture and causes storms on the windward side of the Rockies but as it crests the mountains it is devoid of moisture and as this dry air descends the leeward side of the mountain it rapidly increases in temperature and so will dry out and warm up this leeward side and this area east of the Rockies. It causes snow to sublimate (turn from solid state to a gaseous state). It can dry out plants and soil and will sometimes trigger early sprouting that will then be killed off in a freeze or will not have adequate water as this usually occurs during the cold season and the ground stays frozen or does not get the moisture from the sublimated snow. It can kill off some types of plants and trees that can
