By Jamie Smith
This rolling wall of cloud could easily be mistaken for one giant UFO.
The advancing wedge of white fluffy clouds, followed by a dark storm, looks like the edge of a giant alien aircraft hovering over the land.
The cloud formation, known as a shelf cloud, rolled rapidly across the trees and countryside below, covering everything in a foreboding gloom.
The shelf cloud is the most common type of arcus cloud and forms when cool air descending from a storm cloud cuts underneath warmer air from the surrounding area being drawn into it. As such, they usually herald the arrival of a thunderstorm.
The photos were taken by Belgian photographer Jean-Marie Ghislain in the countryside near the town of Libin in southern Belgium.
Jean-Marie said: “On an early morning drive to the Ardennes I sensed something very unusual developing behind the trees which border the highway.
“It was a sort of intuition.
“I took the first exit to Libin and dashed out of my car with my camera. Luckily I was right on time.
“Within minutes a gigantic arcus cloud, the leading edge of a thunderstorm, took shape under my eyes and rolled over the landscape followed by lightning and rain.
“I’d already witnessed this phenomena in tropical countries due to the important temperature different between the land and the ocean.
“But never did I imagine I would come across one in the middle of nowhere in my native Belgium. It’s absolutely incredible.”