It looked like something brewing in a witch’s cauldron as the skies above Shropshire seethed with strange grey bubbles.
Shoppers stopped and looked skywards open-mouthed, and internet chatrooms were full of debate about the strange sight.
Today weathermen say the bubbles, seen in Telford on Saturday evening, were rare mammatus clouds, lobe-like clusters packed full of ice and rain that appear when thunderstorms are in the air.
This image was taken by Shropshire Star reader Bob Owen, shortly before a sharp shower.
He said: “It was only like it for two to three minutes and I just had to get a picture.”
Another reader, Phil Spencer, said shoppers at the new Morrisons store in Lawley were stopped in their tracks
“Everyone was looking up and saying how odd it was,” he said.
After several torrential showers at the weekend, the outlook for Shropshire remains unsettled, with temperatures typically a chilly 12C (54F).