The sky in Sioux Falls, South Dakota, darkened and turned an eerie shade of inexperienced on Tuesday as a derecho swept by the area.

A derecho is a cluster of thunderstorms and meteorologists will solely classify a windstorm as such if the wind injury will cowl a distance of a minimum of 400 miles.

Onlookers and climate consultants shared pictures of the phenomenon earlier than the storm hit.

In keeping with native Fox Climate meteorologist Heather Brinkmann, the inexperienced coloration is created from gentle refraction inside the thunderstorms and signifies that the storm can be able to producing massive hailstones.

It takes a “super quantity of water content material inside the cloud to realize this coloration, which normally means a considerable quantity of ice (massive hail) needs to be current,” Nationwide Climate Service meteorologist Cory Martin shared in a graphic.

Certainly, there have been later stories of huge golf ball-sized hail in elements of the area.