April 28, 2007 9:11 pm
The Sierra Wave? Yep, that's what they are called. They are technically called Lenticular Clouds, or wave clouds, or lee wave clouds because they form in on the lee side of a mountain. But in the Sierra we call them the Sierra Wave. They are formed by very high winds in the upper atmosphere being forced over the mountains. A lot of times they appear before a storm front moves in. When you see them it means that the winds up there are well over 100 MPH and sometimes over 200.