Re: Strange clouds...

[inet@intellisys.net (brian whatcott)]

At 09:49 AM 5/3/97 EDT, Dwight K. Souder wrote:
....
> the clouds were highly unusual.  They were almost perfectly round, flat
> and smooth on the bottom, and smooth and dome shaped on top.  They were
> all  over the sky and looked like some of the old book covers of where
> earth is being invaded by UFOs or toad-stool mushrooms without their
> stems.
> 	Do these cloud formations have names?  Are they fairly common? 
> What accounts for their strange formation?
There are two candidates for your clouds; they are
1) the standing lenticular altocumulus, or at higher levels,
the standing lenticular cirrocumulus. (ACSL & CCSL)
They are flat base clouds, often isolated, caused by updraft waves over 
mountains, or 
downstream of such geographical features.

2) The cumulonimbus mamma (CBMAM)
This can give a very unusual regular cobblestone appearance to the sky.
This formation is associated with severe weather, violent up/down currents 
and very severe turbulence.

Type 1 is endemic to mountainous regions.
Type 2 is rare but more frequent in tornado alley.

FAA Aviation Weather Services and National Weather Service publication    AC 
00-45C (which may now be out of print) has useful photos of these clouds.

Regards
brian whatcott <inet@intellisys.net>
Altus OK