The first weather class I took in college, Introduction to Meteorology, explained many basic features that a weather geek like myself found fascinating. One process that has been covered numerous times in many different geoscience areas is orographic uplift.
When I initially heard the term in World Geography, I was intimidated by the phrase. However, I later learned over and over again the way a mountain acts as a weather maker. The word “orographic” refers to a mountain while “uplift” addresses the motion that mountains force air to take. It all begins with a parcel of traveling air. Once this parcel reaches a significant obstruction (like a mountain), it is forced upward. One foundation of meteorology is that warm air can hold more moisture, water vapor, than cold air can. Therefore, the parcel of air can hold less moisture as it is forced upward into cooler air. This causes condensation and precipitation on the windward side of the mountain. Once air passes the apex, it warms as it travels down the mountain. The parcel is exhausted of excess moisture at this point, causing dry weather on the leeward side. This process occurs in the western United States because of the Sierra Nevada and Rocky Mountain ranges. For example, parts of California receive adequate rainfall each year while the Midwest, or leeward sides, are desert. The same occurs in western Europe. Although an easy lesson in Meteorology, orogarphic uplift can be a major element in weather.
By the way: For those of you trying to validate the weather folklore from Monday, I have two answers for today.
1) When clouds appear like towers, the Earth is refreshed by frequent showers. These towers refer to a cumulonimbus cloud, a cloud associated with severe weather.
2) Rain foretold, long last. Short notice, soon will pass. I do not claim that this is the original explanation, but the phrase applies for the present day. When there are “popcorn” showers, they are not forecasted days in advance like long-lasting meso complexes are. Keep reading for more explanations!
When I initially heard the term in World Geography, I was intimidated by the phrase. However, I later learned over and over again the way a mountain acts as a weather maker. The word “orographic” refers to a mountain while “uplift” addresses the motion that mountains force air to take. It all begins with a parcel of traveling air. Once this parcel reaches a significant obstruction (like a mountain), it is forced upward. One foundation of meteorology is that warm air can hold more moisture, water vapor, than cold air can. Therefore, the parcel of air can hold less moisture as it is forced upward into cooler air. This causes condensation and precipitation on the windward side of the mountain. Once air passes the apex, it warms as it travels down the mountain. The parcel is exhausted of excess moisture at this point, causing dry weather on the leeward side. This process occurs in the western United States because of the Sierra Nevada and Rocky Mountain ranges. For example, parts of California receive adequate rainfall each year while the Midwest, or leeward sides, are desert. The same occurs in western Europe. Although an easy lesson in Meteorology, orogarphic uplift can be a major element in weather.
By the way: For those of you trying to validate the weather folklore from Monday, I have two answers for today.
1) When clouds appear like towers, the Earth is refreshed by frequent showers. These towers refer to a cumulonimbus cloud, a cloud associated with severe weather.
2) Rain foretold, long last. Short notice, soon will pass. I do not claim that this is the original explanation, but the phrase applies for the present day. When there are “popcorn” showers, they are not forecasted days in advance like long-lasting meso complexes are. Keep reading for more explanations!