Formation of cirrocumulus clouds with virga due to a mass of upper-level unstable and humid air with the high cloud`s precipitation falling underneath very dry air hence subliming long before reaching the ground. This process led to spectecular streaks underneath the cloud cover. The high clouds were so isolated that it dissipated completely with only the precipitation streak remaining. The first thumbnail shows such streaks and the second thumbnail indicate the weather sounding at the time which as explained was typical for the formation of such clouds.