It looks like altocumulus lenticularis, but it is rather deep indeed.
Where was the picture taken, was it near a mountain range?
In that case it could also be an orographic wave cloud.
Have a look here:
and this picture (photograph ??) looks much like Nathan's:
Frank van Lindert
On Wed, 28 Jan 2009 17:07:38 +0000, Chris Barker wrote:
>I thought that, but it's quite deep for a lenticular cloud. I also
>thought perhaps an altocumulus, tending towards an anvil shape.
>But really, I don't think that it's any particular name but perhaps a
>combination of types.
>On 28 Jan 2009, at 11:15, Brian Swale wrote:
>> Chuck wrote
>>> Ah, very pretty. I'm sure there's a name for such a cloud shape
>>> but I
>>> don't know what it is.
>>> Chuck Norcutt
>>> Nathan Wajsman wrote:
>>>> Yesterday afternoon, while walking the dog, the sun was setting and
>>>> cloud formations were all over the place:
>>>> The only function of those clouds was to provide nice colour and
>>>> for my picture; no rain resulted.
>> Lenticular clouds, AFAIK
>> Brian Swale.
Themed Olympus Photo Exhibition: http://www.tope.nl/