Wave Clouds

Some classic wave clouds, or lenticulars, from the front that went through a couple days ago.

The wave clouds in this photo indicate that winds aloft are blowing swiftly to the east (left). Note the iridescence in the brightest and thinnest parts of the clouds in the upper left. Also note the low rotor clouds below the wave, dark and scud-like, especially the one on the right, which may show hints of the rotation typical of these clouds, and which shows a classic ragged form. When conditions are right—when the wave is strong and the rotor is hitting the ground—winds on the ground will move opposite to the winds aloft, typically back to the west in Nevada (right in the photo). These "backwards" ground winds can be strong, erratic, and turbulent, and can cause unexpected damage to street signs and the like. In Nevada, when the rotor is blowing, it's a good idea to keep an eye out for flying sheet metal.

Lenticulars—which are sometimes described as unique, or even rare—are fairly common in Nevada, in the lee of the Sierra Nevada and the many mountain ranges of the Basin and Range.

Understanding lenticular clouds and mountains waves

Lenticular cloud with irisation (cloud iridescence) at Atmospheric Optics

Lenticular clouds at APOD

Photo taken 23Oct2012, Sparks, NV, from the Sheels parking lot.