The sky in the states of Nebraska, Minnesota, San Diego, South Dakota and Illinois in the US turned green due to severe storms. Derecho, which is a form of strong, powerful and straight winds, was the phenomenon that led to the sky appearing green.

Also Read| Madame Tussauds Blackpool places Boris Johnson waxwork outside a job-centre

The green colour was created from light refraction within thunderstorms and it indicated producing large hailstones. Images of the green sky were shared on social media and the surreal phenomenon forced the netizens to repost the images of the sky. These images were mainly circulated through Twitter and Instagram.  The winds and storms that were blowing in the cities caused havoc. It caused major damage to the infrastructure as power lines got snapped and trees were knocked down. It was also reported that the winds blew at 140kph in some areas of the US.

People documented the rare phenomenon on social media and compared it with “Stranger Things”. In a video, a person is heard comparing the sky to that seen in ‘The Wizard of Oz’. A National Weather Services (NWS) meteorologist took to their social media to explain that thunderstorm clouds can glow green when the red light of the sun at the end of the day interacts with the water or ice content in the storm. 

Also Read| ‘Eleven out of ten’ : Amul celebrates success of ‘Stranger Things’

What is a Derecho storm that turned US skies green?

Derecho has its origin from the Spanish word ‘la derecha’ which means ‘straight’. As per the US’s National Weather Service, Derecho is “a widespread, long-lived, straight-line windstorm associated with a band of rapidly moving showers or thunderstorms”. Unlike Tornado there is no rotation in this storm. These storms travel hundreds of miles and cover a vast area. Other than the US, Derecho has also been seen in countries like Germany, Russia, Finland, Bulgaria and Poland. The scientific reason behind the sky turning green is that thunderstorms contain a lot of water in it. The big raindrops and hail scatter away through the blue wavelength of light which slowly combines in the afternoon and evening with yellow light creating a greenish effect.