Definitions for "Sundog"
Keywords:  parhelia, halo, rainbow, ice, phenomena
A luminous spot occasionally seen a few degrees from the sun, supposed to be formed by the intersection of two or more halos, or in a manner similar to that of halos.
A fragmentary rainbow; a small rainbow near the horizon; -- called also dog and weathergaw.
Sundogs are created when some of the ice crystals become large enough to line up in the atmosphere so as to refract the light in a less random pattern. Instead the light is refracted to cause a mock sun to the left or right (or both) sides of the sun. These mock suns are called "Sundogs" or more scientifically - "parhelia". Sundogs are not as common as halos, but can be seen a few dozen times a year, especially in the winter months. They can be a forecasting tools as the thin clouds of ice crystals are often associated with an approaching storm system.