Wednesday, December 21, 2011

Christmas Cloud



This wonderful cloud called a Kelvin-Helmholtz instability, appeared over Birmingham, Alabama this week.
The name is a combination from Lord Kelvin - a Scottish baron who along with German physicist Hermann Helmholtz - came up with an explanation for the freak occurrence.







It's also called a wave cloud and occurs in regions with vast plains where winds quickly change speed creating turbulence.  A fast -moving lighter density cloud, usually a layer of Cirrus cloud, slides on top of a slower, thicker layer, dragging out the surface and creating a wave rolling over water effect.

For more lovely clouds here's the site to visit.

6 comments:

The Elephant's Child said...

How amazing. Thank you.

Marshall Stacks said...

Cloud Appreciation - we haz it. x x

Kath Lockett said...

Awesome! Gotta love that it's called 'Kelvin'. Surely there's a matching Melvin somewhere too...

River said...

What a fantastic cloud! I've never seen anything like it.

JahTeh said...

EC, I could cloud watch all day and frequently do at the bus stop.

Stacks, I ended up buying Gavin Prater-Pinney's book,lovely to dip into.

Kath, you'd be snowflake watching about now.

River, neither have I but I keep watching. We're not in the right area for it but I love watching a thunderstorm build.

Helen said...

It's like a whole flock of Lock Ness Monsters making threatening gestures!

Happy Christmas Witchy!