The day was dominated by formations of thick cirrus clouds (click on the final 5th thumbnail for the photo) which were clearly visible on the visible satellite image (3rd thumbnail). Their formation seems to have been due to a large upper-level trough over the Central Mediterranean with cumulonimbus clouds brewing up over the waters of Northern Libya as the airmass over there was much more unstable. The photographed cloud is a stitched panorama of 3 photos comprising this very rare and exceptionally thick cirrocumulus clouds because of great depth of moisture at upper levels as indicated in the weather sounding (2nd thumbnail) with most of the layer reading a 100% relative humidity. Of course, this upper-level cloud (cirrocumulus) was thick enough to produce precipitation. However, the photographed precipitation streaks evaporated well before reaching the ground due to much drier air underneath the cloud and the fact that it was very high-based. The virga in combination with the cloud itself and sunset made the whole picture seem to be that of a cumulonimbus anvil cloud. However, it was clearly an illusion as no thunderstorm clouds were detected over the Maltese Islands. The first thumbnail shows a closeup of the cloud`s virga.
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