Cloud Cover for a UFO?!?

This photo was taken by Donna Lunsford from her home on Gate 6 1/2, looking toward Mt. Tamalpais.

Donna writes:

What we caught was a lenticular cloud. It was photographed May 20th over a period of 16 minutes, starting at 7:54 PM. I sent it to a NASA friend who said, “These small symmetrical rather self-contained clouds are typically formed downwind of mountain peaks.” Sort of a condensed version of a condensed cloud! It just hung there for about 10 minutes, unchanged, before slowly dissipating. We kept waiting for a UFO to emerge from its cloud cover!