The Cause of Warm, Dry Conditions On The Lee Side
The condition exists because warm moist air rises through "orographic lifting" up and over the top of a mountain range or large mountain. Because of decreasing atmospheric pressure with increasing altitude, the air expanded and adiabatically cooled at the dry adiabatic lapse rate to the point that the air reaches its adiabatic dew point (which is not the same as its constant pressure dew point commonly reported in weather forecasts). Upon reaching the adiabatic dew point, water vapor in the air begins to condense, with the release of latent heat from condensation slowing the overall rate of adiabatic cooling of the air to the saturated adiabatic lapse rate as the air continues to rise. Condensation is also commonly followed by precipitation on the top and windward sides of the mountain. As the air descends on the leeward side, it is warmed by adiabatic compression at the dry adiabatic lapse rate. Because the air has lost much of its original water vapor content, the descending air creates an arid region on the leeward side of the mountain.
Read more about this topic: Foehn Wind
Famous quotes containing the words dry, conditions, lee and/or side:
“A woman moved is like a fountain troubled.
Muddy, ill-seeming, thick, bereft of beauty,
And while it is so, none so dry or thirsty
Will deign to sip or touch one drop of it.”
—William Shakespeare (1564–1616)
“I can’t say that the college-bred woman is the most contented woman. The broader her mind the more she understands the unequal conditions between men and women, the more she chafes under a government that tolerates it.”
—Susan B. Anthony (1820–1906)
“...I am an abolitionist for the sake of my own race—Contact with the African degenerates our white race—I find the association with them injurious to my child—keenly as I watch to prevent it & his faithful nurse to help me ... She is a good woman & so are many of them—Still the race is a degraded one ...”
—Elizabeth Blair Lee (1818–?)
“The most interesting thing which I heard of, in this township of Hull, was an unfailing spring, whose locality was pointed out to me on the side of a distant hill, as I was panting along the shore, though I did not visit it. Perhaps, if I should go through Rome, it would be some spring on the Capitoline Hill I should remember the longest.”
—Henry David Thoreau (1817–1862)