Geograph - photograph every grid square

SC2870 : Unusual cloud, Ballasalla
This looks like a wave cloud, ie, one which is formed by the effects of orographic lifting. In English this means that if an airstream is lifted over mountains or high hills, the air will expand and therefore cool. This reduces it's capacity to hold moisture causing small particles of water to appear as fog or cloud. If this is the case in this picture then there is probably a high hill or mountain in the direction of view causing the uplift. This sort of cloud is pretty rare as it requires the right place and the right air conditions. It is probably more common in the early morning or evening when there are no rising thermals from sun-heated land to upset the flow of air.