Lenticular Clouds

Air and its motions are more often felt than seen, perhaps as an evening breeze stirring spring leaves. Satellite photos of swirling storms and land photos of towering thunderheads reveal air motion as its water vapor condenses into clouds. Another look at air in motion can be seen from the less common stationary cloud, which often takes the form of a lens, or lenticular cloud such as this one lingering over Sheffield a few days ago in an otherwise cloudless sky.
Such a cloud is the result of air moving up over a nearby mountain peak, which elevates the air enough to cool and condense its moisture into the stationary cloud. As the air again descends and warms, the moisture evaporates, leaving the ever-developing cloud behind.
This cloud lasted for a few hours, its smoothly flowing lines following the air's rise and fall as it swept over the nearby peak of Mt. Everett's Dome. As the afternoon sun warmed the air further, it grew smaller, then vanished when its moisture no longer condensed in the rising air.