Clouds roll 1,000km across the sky

A giant band of clouds appeared, making many people rush to leave Sao Conrado beach due to concerns about bad weather.

"When the cloud began to get thicker and darker, everyone noticed it. Some people were worried and quickly left the beach," said Jorge Ricardo, who witnessed the incident. The strange sight made them think that it was about to rain soon, Daily Star on 9/9 reported.

The cloud hovered in the sky for about 5 minutes.

The cloud hovered in the sky for about 5 minutes, according to Sonia Mentes, owner of a stall on Sao Conrado beach."Every activity seems to stop when people watch the phenomenon. The cloud is like a rolled-up towel or a horizontal tornado. It's a very interesting natural phenomenon," Mentes said.

The size of the cloud is much larger than what the camera records, according to meteorologist Jao Caetano from Federal University of Rio de Janeiro."We think the cloud in this case is about 1,000 km long and 2km wide , " he said.

Cloud rolls are often accompanied by cold air.

Such clouds can travel at a speed of 60km / h, weather expert Joselia Pegorim said."The rolling clouds are often accompanied by cold air. They can form when winds above and below a large area blow in opposite directions. Sometimes people panic because they don't often see scenes like So, " Pegorim explained.

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