Skies over Sandbanks

We were treated to a very rare sight over Sandbanks today – asperitas clouds (formerly referred to as Undulatus Asperitas) that look like rippling ocean waves in the sky.

Height of base: 4,000 – 10,000 ft

Shape: Undulating waves

Latin: aspero – make rough or uneven

What is a asperitas cloud & how do they form?

Asperitas clouds are a very destinctive but rare cloud formation, which form on the underside of a cloudy sky make it look like the surface of a rippling, rough sea from below.

The exact way these clouds form is still a mystery to weather experts. However, they do believe that unstable atmospheric conditions, potentially as a precursor to thunderstorm activity althought it was a fairly calm day in Sandbanks when we spotted these. They are apparently also unlikely to yield rain but can be followed by rain inducing clouds.

New cloud type!

“The addition of this previously undocumented cloud formation to the World Meteorological Organisation’s International Cloud Atlas was first proposed by the Cloud Appreciation Society in 2008. Between then and 2015 the case was supported by members of the public sending in images of the dramatic cloud formations.

At the WMO’s 17^th Congress in 2015, the classification was accepted, making asperitas the first new cloud type in over 50 years, since cirrus intortus in 1951.”

The Met Office

Below is a video we created to show you just how wonderful these rare clouds are in person.