Aberlady Sundog

Around 7.30 this evening just behind the dunes on Aberlady Bay I saw this peculiar bright "rainbow" light in the sky just at the end of a long sausage shape cloud and about the same altitude as the setting sun. I have seen something like this before but it was high in the sky on very cold winter's day and this is very different and was very bright. The image here does not really reflect the brightness of the phenomenon.