Taken evening of 17May18. Spreading out of altocumulus clouds due to increasing wind with height from altitudes of around 5.7km upwards where this cloud has formed. It could also have been cirrocumulus stratiformis as the exact cloud height is not clear and there were also 2 layers of clouds possibly adding ‘duplicatus’ to the variety. Some parallel cloud elements on the centre right of the photo was evident showing that it was acquiring the ‘undulatus’ variety because of the wind at the mid and upper levels acting on the cloud. As per second thumbnail, the Islands were under a strong jet stream.