Sun halo

At 14:30 this afternoon there was a very nice example of a halo around the sun also known as a 22 degree sun halo.

The halo is formed by the suns rays passing through high altitude ice crystals and is usually a sign that it will rain within the next 24 hours.

For more information take a look at these links;

http://ww2010.atmos.uiuc.edu/(Gh)/guides/mtr/opt/ice/halo/22.rxml

http://hyperphysics.phy-astr.gsu.edu/hbase/atmos/halo22.html

When I see a distinctive cloud formation, I take photographs at regular intervals as the sky changes and note the resulting weather for future reference.