JamesB wrote:

Hey all.
A few weeks back I caught sight of a very odd looking cloud out of my
window. Has a bit of a nuclear mushroom cloud thing about it! Can anyone
explain how it formed?

http://www.puffle.co.uk/weather.php and it's the last one in "other
clouds". Sorry it's not a great pic, only had my phone handy!

James.

Looks like a not uncommon occurrence where cumulus has convected into a
moist and more stable layer, then spread out into a skirt of Sc, but have
enough energy to then poke through that layer. Then it looks as though it
may have hit another layer and begun to spread out into the mushroom cap.

For another photo of this, see
http://www.wolkenatlas.de/wolken/gvert04.htm - the fifth picture on this
page, Cu congestus.

If you wander through the other pictures in this section - first drop-down
panel "Weitere Galerien" - you might find other examples, or not. Anyway,
there are some great pictures there.


--
Graham P Davis
Bracknell, Berks., UK
Send e-mails to "newsman" as mails to "newsboy" are ignored.