Why Does the Sky Sometimes Turn Green?
You may have heard the myth that green clouds in the sky mean a tornado or large hail is imminent. The evidence suggests that a green sky happens more out of coincidence than any other reason, and it is not indicative of what weather is to come.
In a 1993 study published in the Bulletin of the American Meteorological Society, Bohren and Fraser offered some explanations for why a green sky sometimes accompanies thunderstorms. One explanation is that green clouds appear when the sun starts to lower and the sunlight begins to emit hues of red, yellow, and orange – like a sunset. As that light illuminates the cloud, the reddish hues can be absorbed by clouds containing massive amounts of moisture, which can give the sky a greenish color. But there is no link between a green sky and the likelihood of a tornado or large hail.
However, thunderstorms that are large enough to produce a green sky, often are severe enough where they end up producing large hail and even tornadoes.
What does it mean if the sky is turning green?
Water/ice particles in storm clouds with substantial depth and water content will primarily scatter blue light. When the reddish light scatted by the atmosphere illuminates the blue water/ice droplets in the cloud, they will appear to glow green. A green sky often indicates that large hail will be present in the thunderstorm, but it does not indicate if a tornado is coming.
Why does the sky go green before a tornado?
The sky can sometimes appear green before a tornado due to the way light is scattered by the particles in the air. During severe weather, the air can be filled with small particles such as dust, raindrops, and hail. These particles can scatter light from the sun, which is normally white, into its various components, including green. This causes the sky to take on a greenish tint, which can be a sign of an approaching tornado.
Will there be a chance of a green sky anytime soon for your city? Check out our local weather forecast page to see if there are storms in the forecast for your city.