A few messages suggested a bit more background on Snow Eater Wind would be useful. If there is a barometric pressure gradient across the mountains air will flow over the mountains and then descend down the other side. The air is a gas and will follow what is termed the Ideal gas law. The simple equation is PV = NRT, where P = pressure, V = volume, N = amount of gas (moles), R = gas constant (a number value with an interesting history) and T = Temperature. Hence, if the pressure of the air is increased air will become warmer and if pressure decreases the air will become cooler; other aspects of the equation remaining equal and the gas behaves ideally. Of course there is more to this and that is why we have meteorologists.
Meteorologists use a term called dry adiabatic lapse rate and moist adiabatic lapse rate and for how temperature will change within an air mass. When an air mass descends it will warm because the pressure is increasing. As an air mass descends it will warm at the dry adiabatic lapse rate which is approximately 5.5 degrees F for every 1,000 feet the air descends.
The strong east winds that reached Bellingham and Skagit County as well as the lower west slopes of the Cascade Range to the south were the result of a high pressure mound of air east of the Cascades with a low pressure off the coast of Washington. The high pressure air flowed towards the low pressure and as it descended it warmed at the dry adiabatic lapse rate. Even if the original air mass pulled over the mountains may have been cold, the increase pressure would cause it to warm substantially. The roughly 7,000-foot drop over the North Cascades Range would produce a warming of the descending air mass of 38.5 degrees F. So an air mass of say 10 degrees F would warm to 48 degrees F, about the temperature spike Bellingham had for a few hours last Wednesday evening.
Technically this is not a Chinook wind per meteorology, but the results are very similar and I would note the term Chinook wind is used more broadly by some and I do not know if the type of wind that descends east from the Cascades has been given a name.
Billy and I experienced our share of Chinook winds and he alerted me to this song by Jack Gladstone, a Blackfoot and former U of W Husky.
Meteorologists use a term called dry adiabatic lapse rate and moist adiabatic lapse rate and for how temperature will change within an air mass. When an air mass descends it will warm because the pressure is increasing. As an air mass descends it will warm at the dry adiabatic lapse rate which is approximately 5.5 degrees F for every 1,000 feet the air descends.
The strong east winds that reached Bellingham and Skagit County as well as the lower west slopes of the Cascade Range to the south were the result of a high pressure mound of air east of the Cascades with a low pressure off the coast of Washington. The high pressure air flowed towards the low pressure and as it descended it warmed at the dry adiabatic lapse rate. Even if the original air mass pulled over the mountains may have been cold, the increase pressure would cause it to warm substantially. The roughly 7,000-foot drop over the North Cascades Range would produce a warming of the descending air mass of 38.5 degrees F. So an air mass of say 10 degrees F would warm to 48 degrees F, about the temperature spike Bellingham had for a few hours last Wednesday evening.
Technically this is not a Chinook wind per meteorology, but the results are very similar and I would note the term Chinook wind is used more broadly by some and I do not know if the type of wind that descends east from the Cascades has been given a name.
Billy and I experienced our share of Chinook winds and he alerted me to this song by Jack Gladstone, a Blackfoot and former U of W Husky.
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