What does AC stand for?

He proposes they be called altocumulus undulatus asperatus.

It turns out the 'saucer' is nothing more than Altocumulus Lenticularis - a rare lens-shaped cloud that forms when moist air flows over mountains.

CAPTION(S): EVENING GLOW: Brian Hutchinson of Hartburn, Stockton, photographed this spectacular sky of altocumulus clouds in Hartburn, left; GO WITH THE FLOW: Young photographer, Laina Christie, aged ten, captured this peaceful stream and woodland near Osmotherley, below; NATURE: A Mistle Thrush in the snow, photographed by Brian Swales of Letch Lane, Stockton, on January 3, above.

ALTOCUMULUS 6,000 TO 20,000 FEET These form textured clusters.

It turns out the 'saucer' is nothing more than Altocumulus Lenticularis - a rare lens-shaped cloud that forms when moist air flows over mountains.

Divided into sections devoted to low, middle, and high clouds, this field guide to the skies includes such details as the ferocious, storm-producing capabilities of the cumulonimbus, the UFO-like appearance of the altocumulus lenticularis, and the halo-forming tendencies of the cirrostratus.

It turns out the 'saucer' is nothing more than Altocumulus Lenticularis - a rare lens-shaped cloud that forms when moist air flows over mountains.

Mackerel scales are altocumulus clouds which look like fish scales.