Gallery 3 - Earth Bound   >   Clouds   >   Cirrostratus

Cirrostratus clouds commonly produce halos because they are composed almost entirely of ice crystals in the upper atmosphere. These clouds are thin enough that the sun and moon can shine through them. The appearance of these thin streaky clouds often forecast rain 12 to 24 hours later. This image was taken midday in summer with the sun directly overhead. Photo by Debra

These cirrostratus clouds late in the day made a very striking halo around the sun. Photo by Peter