A terrego is a large storm with a diameter of 400 km. The event is moving rapidly across the country and may bring hurricane-like winds, heavy rain and thunderstorms. The storm type is more common in the interior of the United States, but the sky rarely changes color.
Calm before the storm
According to the National Weather Service (NWS), US KNMI, the sky changes color before or sometimes during a storm. According to Peter Rogers, a meteorologist with the NWS, this is due to the way the sun shines on certain particles in the atmosphere. The New York Times†
“It must have gotten a lot of attention,” Rogers says. Green skies were mostly seen in and around downtown Sioux Falls, where many residents filmed the event and posted it on social media.
According to the NWS, the green color may indicate hail during the storm. It didn’t happen much, but it rained in some places. In the neighboring state of Minnesota, a baseball-sized hailstone was discovered.
A strong wind blows
The terrego brought strong winds, reaching nearly 100 miles per hour in some places. The storm’s total damage was unknown, but there were no casualties near Sioux Falls, where the sky turned green. However, some buildings, trees and power cables were damaged.
Central American states, collectively referred to as the Great Plains, are more likely to experience such storms. In the summer of 2020, a terrego caused massive damage. 250,000 people were without power, and the storm killed four people.