A large supercell was seen over Burlington, near the Colorado-Kansas border, on Sunday, May 27.

Storm chaser Francis Lavigne-Theriault called the huge storm a “mothership” for its looming alien appearance.

Denver-based 9NEWS said a tornado warning was issued for the area, while the National Weather Service Burlington warned the tornado threat would continue into Monday. Credit: NZP Chasers via Storyful