Undulations within the cloud layer usually to air turbulence and usually associated with strong winds aloft. However, at an altitude of 6.4km (where the cloud was formed according to the weather sounding) showed only Force 7 SW wind and shear just above that level. However, conditions might have been just right for this cloud to form. The first thumbnail shows the formation of cirrus spissatus taken on the same morning. These clouds were the result of a surface low pressure over NW Libya as indicated by the surface wind chart due to the strong sun`s rays during that time of year. Almost dry thunderstorms were observed on the previous night.