This morning I noticed a beautiful ‘smile in the sky’ or ‘upside down rainbow’ in the clouds above the rowan tree.  Unlike a rainbow which is formed with rain, this is a Circumzenithal arc formed with sunlight being bent through ice crystals in the high altitude cloud and separating the colours with the red at the bottom. It occurs only when the sun is below 32.3 degrees high and is best when the sun is about 22 degrees.  Generally cirrus clouds foretell a change in the weather with a change today from a beautiful sunny morning to cloud and rain later and the nearby contrail of a plane from Helsinki to Dublin shows that the temperature there must be damp and very cold at that height.
Thanks to Bobsblips for his challenge this week of ‘Weather’.