Dust devil causes stir

Viral videos showing whirling dust devils have been making the rounds in Cayman.

National Weather Services Director General John Tibbetts has said the natural phenomenon is not uncommon and are usually signs of atmospheric instability.

He said the weather service recorded an increase in low level cumulus clouds at 4 pm on Saturday.

“On Saturday April 18th, 2020 at around 4:30 pm a spinning column of air or a dust devil was observed at the Foster Food Fair parking lot near the Owen Roberts International Airport. A Dust Devil is a whirlwind of air into which dust and debris gets caught up, making it visible,” he said in a brief statement to the Cayman Compass on Monday.

One of the videos, which runs for over 2 minutes, shows the swirling wind funnel whipping into a frenzy as vehicles try to navigate round it.

A second video showed a swirling funnel on the water’s surface at a local dock.

He said dust devils form through a different mechanism than tornadoes, and are much smaller, usually only 10 to 50 feet in diameter, and usually not extending more than 100 feet into the air.

“They usually are seen during relatively dry conditions, when sunlight is providing strong heating of the surface, and when winds are generally light. Dust devils produced wind speeds reaching 25 to 30 mph lasting from a few minutes up to half an hour in extreme cases,” Tibbetts explained.

He stressed that the mechanism of a dust devil is “completely different from that of a tornado.

“A tornado forms from a supercell thunderstorm, which do not form on the Cayman Islands,” he added.

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