George:

While not as impressive as most Lenticular clouds, I found these two relatively rare Lenticular clouds over western Albemarle County off Garth Road on the morning of February 18, 2004.

Known meteorologically as "altocumulus standing lenticularus", Lenticular clouds are lens-shaped clouds that can result from strong wind flow over rugged terrain.

The strong flow produces a distinct up and down wavelike pattern on the lee side of the mountain or large hill and the lenticular clouds tend to form at the peaks of these waves (or oscillations).

They sometimes are very round and the edges are so well defined that they resemble flying saucers. I think one of the largest of these types of clouds I have seen can be found in this photo taken in Hawaii: http://antwrp.gsfc.nasa.gov/apod/image/0312/lenticular_hawaii_big.gif.

Strangely enough we do not have quite the rugged terrain as they do in Hawaii or in the midwest where you can sometimes find lenticular clouds. So you can see, I was obviously impressed enough to pull over and snap a couple of shots.

These clouds dissipated after about six minutes as the sun rose.

Will Lyster (electronic mail, March 6, 2004)