An unusual electrical storm called "derecho" in the South Dakota region of the United States painted the skies green on Tuesday, baffling the residents of Sioux Falls city.
"Derecho" is a wind storm that generally comes together with electrical storms, and it normally extends to hundreds of kilometers. In the case of the one in South Dakota, it traveled almost 2,000 kilometers, affecting near states of Nebraska, Illinois, Iowa, Minnesota and Montana, according to the local media.
Social media users shared images of the green sky after the storm that swept over the Sioux Falls region.
Meteorology experts signal that, although severe weather is usually seen with a green sky, there is no correlation between them and that this phenomenon has not been studied thoroughly until now, the website specialized in weather AccuWeather says.
However, explaining why the eye sometimes perceives it as green, it claims that it is the clouds of heavy storms that directly affect the manner sky's color is perceived.
The meteorologist of AccuWeather, Isaac Longley, explains this by saying that the green color of the sky might happen because of the light's role in some events like electrical storms and sunset.
"As many of us know, the sun appears redder later in the day as it approaches the horizon. However, light underneath a tall thundercloud appears blue due to the scattering by water droplets," he said.
"When the blue light is illuminated by the red light from the setting sun, it appears green, which is why some thunderstorms have that greenish hue to it"
Furthermore, Cory Martin, meteorologist of the national service of the United States, published an inphography where this idea is elaborated furthermore, adding that "this phenomenon is usually a visual warning signal that the storm is capable of producing a very big hailstorm."
