03.25.10
Green Sky
Have you ever heard that when the sky turns green, it means a tornado is coming?
This saying is an oft perpetuated myth, especially in the central US. Truth be told, no one knows for sure what causes a green sky to form. Somehow it’s not a high priority in science right now. 🙂 One thing we do know, though…green skies are often observed with severe thunderstorms, but the sight of a green sky by no means indicates that a tornado is about to form or large hail is about to fall.
Although we are not sure what the exact mechanism is behind the green sky (there are multiple theories you can find on the Internet; some have more credibility than others), the color is likely a result of the liquid water and hail in some strong thunderstorms. Water absorbs and re-emits longwave radiation very well. In fact, water vapor contributes to the greenhouse effect more than any other gas in the atmosphere. One theory is that when sunlight reaches the water droplets and ice within a thunderstorm, the red light is absorbed somewhat, while the green light is reflected back to our eyes. The heavier the precipitation, perhaps the greater the color green.
I chose the name “Green Sky Chaser” for my website and blog because I love the color green. My favorite color of all is a combination of green, blue, and gray: the practically indescribable, pale turquoise color of a stormy sea, and best of all the awe-inspiring color of the sky during some amazing severe storms. I have witnessed several brilliant, blue-green skies while storm chasing (see photo, above; for more photos from my storm chasing adventures, see my website). To me, a green sky means ominous, breath-taking beauty. Tornadoes are not my sole purpose for chasing; the sight of a tornado may be the icing on the cake, but I’d travel many miles just to see lightning, hail, amazing storm structure, and an awesome green sky.