Formation of cirrus uncinus clouds just before sunset well ahead of an upper-level warm front as a low pressure system over Africa was moving eastnortheastwards as per surface pressure chart on the fifth thumbnail. These were invading cirrus clouds as could be proved by the panoramic high cloud photo on the first thumbnail and which was observable even on the visible satellite image of the fourth thumbnail taken at 1400 CEST. As could be noticed in the photo, the high cloud is terminating in the form of a comma or tuft pointing outward away from the wind direction at high altitudes being the WNW wind according to the weather sounding on the third thumbnail. However, parts of the cirrus in the panorama did contain some rounded protuberance. Lots of wind shear was available at high altitudes along with a very strong jet stream where the clouds had formed at least 7.4km above sea-level and being triggered by a frontal system. The second thumbnail is a sunset photo showing kelvin-helmholtz like features at the top of the photo further proving strong shearing at that level. The following day was followed by cloudy conditions with lots of mid-level clouds.