Formation of cirrocumulus clouds in the afternoon due to a positive upper-level vorticity indicating high-level instability as shown in the 500mb chart on the fourth thumbnail. According to the third thumbnail weather sounding, the photographed clouds could have been altocumulus at upper-levels with the lowest height formation being 6.2km. However, due to the very small cloud elements (much less than one degree width) which was the most striking feature, I am almost certain the photographed cirriform clouds were at altitudes of above 7.5km possibly even around 8km where wind shear was present. This change in wind speed with height managed to produce very small ripples on the thin cloud cover making it of the variety ‘undulatus’ as can be clearly observed in the second thumbnail photo taken about 15 minutes later from the main photo as the cirrocumulus clouds continued to evolve. At the top of the main photo, honey-comb like features were noticed hence containing parts of the ‘lacunosus’ variety whereas parts of the cloud elements looking like small grains were barely visible. The first thumbnail shows the whole cirrocumulus clouds itself in bands aligning with strong upper-level winds blowing from a Westerly direction.
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