Rare colorful clouds

Yesterday, one hour before sunset, I did see some colorful clouds in the opposite direction of the Sun (At the Anti solar point). I never seen colored clouds there before so I had a hard time figuring out if they were polar stratospheric clouds or iridescent clouds. The colored clouds slowly faded away as the sun set so I thought it might be iridescent clouds, but I never seen them opposite of the Sun before.

When I returned home I contacted Les Cowley at OPOD (http://www.atoptics.co.uk) to get his opinion of these clouds and he guessed that it's tropospheric iridescent clouds. He's never seen them opposite the sun before so this is probably very rare.

Always exciting to see a new phenomena, perfect ending for 2017.

Happy new year everyone!