Lee wave

Lee waves are waves in a stream of air when the wind moves over mountains. Lee waves allways occure in groups at the wind abandon site (lee) of mountains. Usually a horizontal turbulence is generated at the lee side of the first moutain (following the air stream), the so called rotor.

Both, lee waves themselves as well as the rotor may be indicated by typical cloudes in shapes of lenses (lenticularis) which do not move with the wind as cloudes usually do.

Lee waves provide a possibility for gliders to gain altitude when soaring.