cshimokita[Photo Forum Moderator]
10714
BigAppleBill beat me to it...
Lenticular clouds are stationary clouds that form mostly in the troposphere, typically in parallel alignment to the wind direction. They are often comparable in appearance to a lens or saucer. Nacreous clouds that form in the lower stratosphere sometimes have lenticular shapes. ― Source Wikipedia
Altitude: up to 12,000 m; (40,000 ft)
Appearance: lens-like, Saucer-shaped
Casey
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