Why do storms turn green?
Aliens? Surface of the ground? Hail?
How about…none of the above (except maybe aliens).
The answer actually lies within a simple trick of light. Storm clouds are inherently blue and sunlight tends to be orange or red — put those two colors together and you end up with green of some sort.
So not magic. Not a refraction of ice — just good old fashioned tricks of light.
Here’s the full explanation…
A Trick of Light
With the orange-red sunlight hitting the blue tinted clouds increasing, the visible light within the clouds likely becomes greener.
But Wait, its Not Hail?
The green color in storms isn’t directly linked to hail. While hail helping turn clouds more green can’t be fully discounted — storms without hailstones have been recorded at green wave lengths just like storms with green hailstones.
So let’s put this to rest right now: green clouds do not mean hail is coming. But green clouds also don’t mean hail is not coming. The color of the sky doesn’t indicate the presence of severe weather threats.
You can see Dr. Frank Gallagher’s powerpoint presentation on storm colors here. If you want heavier reading, here’s a scientific paper on the subject.
Does a Green Sky Mean Tornadoes?
Another myth associated with green skies and storms is that they signal a tornado is imminent. This is definitely not true, as green skies are likely more often associated with non tornadic storms than with tornadic storms. The color of the sky actually has nothing to do with what severe weather threats are incoming.
Like this post? Learn about the basic parts of a supercell (and where you can find hail) here. Also, learn about the different types of supercells here.