Lee Wave

Lee waves are a type of mountain wave that are caused by a strong wind flow crossing over some type of barrier, such as a mountain range and constrained to a narrow depth of the atmosphere. Since the phenomena is directly related to the barrier, lee waves are stationary with respect to the barrier.

• Lee waves can produce turbulence downwind of the barrier. This turbulence is usually constrained to within a few thousand feet of the barrier and below. This turbulence can cause a rapid change of airspeed and altitude for aircraft.
• Lee waves can lead to changes in wind speed as well as strong up and downdrafts.
• The wave action of lee waves can also create conditions favourable for rotors (turbulent eddies) beneath the area of lee waves.