SUBSCRIBE NOW AND SAVE 3 months just 99¢/month



WeatherTalk: Sun dogs are not always a sign of cold weather

The sun dogs Monday morning were caused by snowflakes suspended in the air following the Sunday night blizzard.

Weather Talk.jpg

Sun dogs are often seen in our region in cold morning air following a snowstorm. Many people, therefore, associate sun dogs with cold air, even thinking that one causes the other. However, this is not quite right. Sun dogs are a refraction of sunlight caused by ice crystals in the air. The crystals work sort of like raindrops, but with different mechanics, to bend and separate the light into colors.

The ice crystals that caused the sun dogs Monday morning were actually windblown snowflakes suspended in the air following the Sunday night blizzard. Thin clouds can also cause sun dogs if the clouds are made of ice. This method can produce sun dogs in hot summer weather but summer sun dogs are not as bright because clouds made of ice are much higher up and so farther away. In extremely cold weather, water vapor will spontaneously freeze and so very cold weather is one cause of sun dogs, but not the only one.

What to read next
Winter weather advisory in effect through 3 p.m. Friday, Jan. 21.
Strong eruptions in the tropics have been known to cause cooling due to large amounts of sulphur dioxide being placed into the upper atmosphere.
A modest shift could easily leave our region with more air from the southwest and with much milder and drier weather.
The Herald has been naming blizzards for more than 30 years.