In scenes reminiscent of a Hollywood blockbuster movie about alien visitors, footage has emerged showing an extraordinary cloud formation looming over a US town.

Striking images show the enormous shelf cloud, a form of arcus cloud, that appeared above Clovis, New Mexico.

Christian J Hernandez, who shot video of the cloud, said: "The sunset was beautiful as a stunning mothership cloud moved closer into town that evening."

The US National Weather Service explained that shelf clouds were often associated with squall lines, and are frequently reported as wall clouds, funnel clouds, or rotation.

"The main threat with any squall line is severe damaging winds associated with the shelf cloud, although brief spin-up tornadoes can occur," the service said on its website.

"Often times, these tornadoes are rain-wrapped and short-lived."

© Sky News 2020