Unusual rime ice photo looks like frozen tornado on Mount Washington

NORTH CONWAY, N.H. - A researcher at the Mount Washington Observatory in New Hampshire took an incredible photo Thursday of something that looked like a frozen tornado. It's called " rime ice ."

What is rime ice?

Rime ice is a fairly common phenomenon on Mount Washington this time of year and throughout the winter season.

In order for rime ice to form, you need to be in a cloud (or fog), with temperatures below freezing and, to create some amazing structures, have a decent amount of wind.

Clouds are made up of millions and millions of very tiny water droplets.  When the clouds are in an airmass that is below freezing, these droplets become supercooled.

When the droplets make contact with a surface that is also below freezing, they begin to stick and accumulate. Add in a stiff wind and you can get some really cool and interesting rime ice formations.

Since Mount Washington is in the clouds about two-thirds of the time and temperatures average well below freezing, you could call it the rime ice capital of the world!

Weather observers up there need to constantly chip the ice off of the instruments outside. Many times, it forms so quickly, it can accumulate at clips of nearly 10 inches per hour.

Rime ice and airplanes

Rime ice is also a concern for aircraft.

When flying high in the atmosphere, where temperatures are almost always below freezing, rime ice often adheres to the wings of planes.

The main concern is that this could alter the aerodynamics of the wings, therefore de-icing equipment becomes a necessity.