The Helm bar, which is the white bar of cloud that you can see in the picture, is associated with the Helm wind which is the only named wind in the British Isles. The bar is a roll of cloud that is formed by a cold easterly wind blowing down the side of cross fell and meeting warmer air rising from the Eden Valley. It is then swept back up by the warm air forming a roll of cloud just in front of the Pennines. There is often a clear spell in front of the hill and the cloud above the bar very black as you can see in the picture. The bar is often accompanied by a very strong wind which can blow people off their feet and sometime sound like an express train. This is the Helm wind. Our daughter was once at the bottom of the fells when the helm wind was blowing and she said it was very strange because the wind was blowing in her face but the clouds above her were blowing from behind her.
This is straight out of the camera with no processing at all. Possibly best viewed on black.
Very impressive Shirley. We have a roll cloud phenomena that presents in North Queensland Australia called the Morning Glory frequented by glider pilots :)
