Back in August as I was driving along my street towards my home I noticed that the clouds in the west looked icy as the sun was setting. As soon as I arrived home I grabbed my camera and began photographing the clouds as the sun sank behind the horizon.
In winter is not that uncommon for rainbow or prism like effects to appear in the clouds. The sunlight passes through the icy clouds, breaking up the light into its constituent colours. These clouds would probably be considered to be iridescent or maybe even nacreous clouds.
As time passed the prismatic effect became more pronounced. The colours of the rainbow began to appear at the edges of the clouds as the sun dropped lower in the sky. In some cases entire sections of the clouds were daubed with colours.
Then, as the sun had set beneath the horizon the high prevailing winds began to distort these high altitude clouds and strange shapes appeared in the sky. First of all an interesting wave like cloud appeared.
Then, as time passed the same cloud evolved into a ravenous creature bent upon consuming all that lay before it as is crept silently across the sky.
If you examine the photographs below you can see how these effects grew and evolved over time. Amazing is the fact that some of the clouds were clearly casting lengthening shadows upon others as the sun sank lower behind the horizon.