Formation of cirrocumulus stratiformis undulatus clouds just before sunset ahead of a weak upper-level trough that was approaching the Maltese Islands from the NW. This patch of cloud was even visible from space as per seventh thumbnail. The strong jet stream on the eighth thumbnail had produced plenty of wind shear to make the whole cloud rotate photographed. The first two thumbnails show panoramic views of the ripples covering the whole sky from one horizon to another which is very rare from such cloud species making the sky look a spectacular ripple. The third thumbnail seemed to hint at more than one layer of cloud possibly a set of altocumulus under cirrocumulus, always of exactly the same species and variety. The fourth thumbnail is a panoramic view of the third thumbnail to illustrate what was stated earlier. The fifth thumbnail shows the definite approach of altocumulus from the grey shading in the background synonym with such cloud description. In fact, the weather sounding on the sixth thumbnail produced two cloud layers one at an altitude of between 3km and 3.6km and the other at between 6.4km and 7.4km. The highest cloud level had plenty of wind shear to make it of the variety undulatus with the WSW wind increasing from 65kmh to 105kmh as the strong jet stream level was reached.
Further similar cloud photos of the day were taken and are available upon request. Humidity at the surface was very low at just 30%.