Bizarre footage of an orange mushroom-like cloud appearing over Portugal has been compared to a scene straight out of apocalyptic blockbuster Independence Day.
The incredible footage shows the cloud spanning a huge distance across a highway. Clips from another two angles show lightning under the cloud formation.
It was captured on March 20 and has gone viral on YouTube after being shared by conspiracy theorist Disclose Screen.
The YouTuber said the clip first appeared on Facebook with a caption: “Does anybody knows what’s going on?”
He said: “No information was given but I do get from the comments that the language is Portuguese.
“I’m not saying this is anything unnatural but this is one hell of a capture.”
He added that the cloud gave off a “fiery Independence Day” effect, saying: “I’m no Bible nut but as told, there will be signs in the skies.”
Viewers have since flocked to the comments section to voice their amazement at the clip.
One said: “Looks like entities revealing its arrival from depths…unknown.”
Another wrote: “We are all gonna die today!”
Grahame Madge, a spokesman for the Met Office, has since explained to Daily Star Online that the cloud is known as a cumulonimbus cloud.
He said: “Currently there are unsettled conditions across parts of Iberia and North Africa.
“One of the features of this unsettled weather has been the development of thunderstorms, from cumulonimbus clouds.
“These towering giants can build until they reach the top of the troposphere – the part of the atmosphere containing our weather.”
The anvil shape was formed once the cloud failed to climb and fanned out, he said.
“Cumulonimbus clouds are a familiar feature in the skies above Europe, including the UK given the right conditions,” Grahame added.
“When they are backlit by the sun [as in this case], the details of their ominous and vast form can be best appreciated.”
Last week, a mesmerising roll cloud appeared on the shore at Rhode Island in the US.
Stunned viewers likened the sight to a scene from apocalyptic blockbuster The Day After Tomorrow.
But meteorologists explained that the scene typically associated with unstable air and thunderstorms.