This layer of Cirrus clouds slowly developed in the late afternoon.
It became denser and denser, until a significant part of the sky
CsUnd4.jpg and CsUnd5.jpg:
The wave structures of this Cirrus layer indicate strong turbulences
in the upper troposphere. They most probably result from shearing
between overlapping flows from different directions.
CiStrUnd1-3.jpg: S. Borrmann, Pulpit Rock (Kanzelhöhe), Carinthia,
Austria, December 2001
CsUnd4+5.jpg: S. Borrmann, Ingelheim, Germany, 27 February 2002