Cloud-busting: Mare's tails

4 July 2016

Pretty, wispy clouds have been filling your reports today (Monday 4 July).

These are a type of cirrus cloud known as cirrus uncinus. The name is derived from Latin and means "curly hooks".

The clouds occur at very high altitudes, at a temperature of about −50 to −40C.

They are commonly known as mare's tails because of their likeness to horse tails. An old weather proverb goes, "Mare's tails and mackerel scales make lofty ships to carry low sails."

Together, cirrus uncinus clouds and patchy altocumulus clouds often mean that rain is on its way.

Here is a selection of the gorgeous mare's tails you have been posting.

Clustered mare's tails that look like a feather — Image caption,
These clustered mares' tails appeared feather-like in Chelmsford, Essex

A row of wispy clouds in a field — Image caption,
Row of mares' tails seen over Cambridge, Cambridgeshire

Wispy cirrus uncinus clouds over houses — Image caption,
Wispy cirrus uncinus clouds across Bradshaw, Bolton

Cirrus uncinus over country landscape — Image caption,
These great mare's tails were seen over Meltham, Kirklees

Cirrus uncinus over country landscape — Image caption,
Mare's tails over Hoyland Nether, Barnsley

Cirrus uncinus in a blue sky — Image caption,
Pretty cirrus uncinus over Sleaford, Lincolnshire

A sky full of mare's tails — Image caption,
A sky full of mare tail clouds in Stafford, Staffordshire

Wispy clouds in a blue sky — Image caption,
These wispy beauties were captured over North Frodingham, East Yorkshire