The Sierra Wave is a dramatic weather phenomenon on the eastern side of the Sierra Nevada Mountains, especially near places like Owens Valley. It’s a type of standing wave cloud, formed when stable, moist air is pushed up over the mountain range and then descends on the leeward (downwind) side.
Here’s a simple breakdown of how and why it happens:
- Wind hits the Sierra Nevada: Westerly winds (from the Pacific Ocean) blow moist air toward the tall Sierra peaks.
- Air rises and cools: As the air is forced up the mountains, it cools and condenses, forming clouds. This is the start of a lenticular wave pattern.
- Wave formation: On the eastern side, the air sinks, warms, and then rises again in a repeating up-down wave pattern, like ripples in water.
- Stationary clouds: If there’s enough moisture, lenticular clouds form at the crests of these waves. These are the classic “Sierra Wave” clouds—smooth, lens-shaped, and often stacked like pancakes.
- Why they matter: These waves can cause extreme aircraft turbulence but also create ideal lift for gliders. Owens Valley is world-famous for sailplane pilots who “ride” the Sierra Wave to high altitudes—sometimes over 30,000 feet.
In short, the Sierra Wave is caused by strong winds, stable air, and the massive barrier of the Sierra Nevada, producing a beautiful but sometimes dangerous atmospheric wave on the eastern slope.