| shantroy |
01-22-2008 08:55 PM |
Slimming & gatoramand: I think only people who have lived in western canada know what a chinook is, sorry bout that. Basically a chinook is a warm wind that generally comes from the west. Calgary, where I'm from get's them all the time in the winter. A chinook can bring the temperature up 15 degrees or more in the span of a day. For example it was appox -20F yesterday with the windchill and by noon today is was 36F. Chinooks are most common in south central alberta and become less common the further south, and east you go. As a side note chinooks often cause the coulds to form beautiful arches in the sky. Go to Google images and goodle chinook arch and you'll see what I mean. Chinooks also cause migraine headaches, due to the the change in barrametric pressure.
This is from wikipedia:
The eastern-slope chinook phenomenon is a Föhn wind that 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 and falls out as precipitation, warming the air by releasing latent heat. Then the air is warmed and dried by adiabatic compression as the air descends the leeward side of the mountain range.
Warm air descending the slope can also displace an existing cold, moist air mass, enhancing the temperature increase and moisture decrease observed with the Chinook.
The turbulence of the high winds also can prevent the normal nocturnal temperature inversion from forming on the lee side of the slope, allowing nighttime temperatures to remain elevated.
Quite often, when the West Coast is being hammered by rain, the windward side of the Rockies is being hammered by snow (as the air loses its moisture), and the leeward side of the Rockies in Alberta is basking in a chinook.
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