- A rare "roll cloud" was observed by beachgoers at a beach in Portugal on Sunday.
- The sighting occurred as Portugal is experiencing a heatwave with temperatures reaching highs of 42C.
- This dense, tsunami-like cloud forms when hot and cold air masses collide, condensing into a curved shape.
- Climate expert Mário Marques noted that while not unprecedented in Portugal, this phenomenon is more commonly witnessed in places like Australia.
- Watch the video in full above.
IN FULL