The sky in the Sioux waterfall area (South Dakota, USA) turns green before the storm hits – Photo: DAILY MAIL
According to the US National Weather Service, the “root” cause of the sky turning green in South Dakota lies in the composition of liquid water in the air.
Blue skies occur when clouds carry a lot of water and allow a stream of blue light to pass through before the storm hits. The blue light combined with the red light of the sun causes the sky to turn green.
USA Today reported that a major storm swept through the state of South Dakota on July 5 with winds of up to 93km/h and a hailstorm with wind speeds of 159km/h.
Earlier, the US National Weather Service also confirmed on 5-7 that a “derecho” storm had swept through much of South Dakota, Minnesota and Iowa, leaving nearly 30,000 people without power for several hours.
“Derecho” is a large-scale storm associated with high winds, showers and high-speed thunderstorms. If the wind lasts about 400km, it is considered a gust of wind.
According to the New York Times , inclement weather is one of the reasons why storms and thunderstorms have repeatedly hit the South Dakota area in recent days.
“Irregular coloration of the sky before or during a storm sometimes occurs depending on how sunlight interacts and scatters with other light components in the atmosphere,” said Peter Rogers, climate scientist meteorologist from the Office of the Weather Service in the Sioux Falls area, said.
Meteorologist Cory Martin further explained: “It takes a large amount of water in the cloud to achieve this color. This phenomenon is often a visual warning sign that a thunderstorm has the potential to produce very large hail. “.
The Sioux Falls Authority said the green cloud lasted about 30 minutes with black, blue and brown clouds during heavy rain from Huron City (South Dakota) to Iowa on 5-7.
According to the New York Times , a powerful “derecho” storm in August 2020 destroyed several homes, crops and left more than 250,000 people without power across Iowa and Illinois.