Mackerel sky

Our third and final day of this session of tree surveying - only nine more days to go! We were all feeling rather tired after the heat of yesterday, but fortunately today was much fresher, which allowed us to speed ahead and get our target area completed. There was a mix of sunshine and cloud, and towards the end of the afternoon this glorious mackerel sky developed.

Wikipedia states that a mackerel sky or buttermilk sky is an indicator of moisture (the cloud) and instability (the cirrus-cumulus form) at intermediate levels (2400-6100 m, 8000-20,000 ft). If the lower atmosphere is stable and no moist air moves in, the weather will most likely remain dry. However, moisture at lower levels combined with surface temperature instability can lead to rainshowers or thunderstorms should the rising moist air reach this layer. In the winter it is often said to precede snowstorms and flurries.

Mackerel skies are spoken of in the popular bywords, "Mackerel in the sky, three days dry," "Mackerel sky, mackerel sky. Never long wet and never long dry," and the nautical weather rhyme, "Mare's tails and mackerel scales / Make tall ships carry low sails." The phrase 'mackerel sky' came from the fact that it looks similar to the markings of an adult king mackerel.

The drive home was uneventful, and Pete had cooked an amazing chinese chicken and chestnut stew for our dinner, which was totally yummy. After that we all sat down and watched the Olympic opening ceremony. I had been rather sceptical about the hype, but was blown away by it all - Danny Boyle produced a creative masterpiece that really captured a lot of the best features of Britain - particularly our scientific and artistic creativity and quirky sense of humour. I especially loved the forging of the Olympic rings and the giant flower-like structure holding the Olympic flame was truly beautiful.