Iridescent lenticular clouds on Sep 27, 2017

Lenticular clouds are formed when moist air is lifted and lowered. That can be happen at mountains (lee waves), if layers with different wind directions causes turbulence or by shear winds created at a weather front. When the air is lifted and cooled the moisture condenses. As soon the air is lowered again the water droplets evaporate. Lenticular clouds are more or less stationary.

The water droplets within a region of a lenticular cloud have a similar lifetime and are therefore similar-sized. This are perfect conditions for irisation, a colorful phenomenon caused by diffraction and interference on uniform objects.

In the picture and video presented below some lenticular clouds where captured by a sky surveillance camera pointed to south. In the second half of the video a quite stable cloud is formed directly in front of the sun. Irisation (colored stripes and patches) and coronas (same effect but circular shape) can be seen in the clouds.

Click on image or use the buttons to start a video.

Observation data:

Date:	Sep 27, 2017 between 11:17 and 12:53 CEST (=UTC+2h)
Location:	Pulsnitz, Germany
Instrument:	Sky surveillance camera pointing to south