Monitoring the Tropics, Week 4: Saharan mud blankets Caribbean as Tropical Storm Dolly varieties within the northern Atlantic

SAN JUAN, Puerto Rico (AP) – A giant cloud of Saharan dust covers the Caribbean on its way to the United States with a size and concentration that experts say has not been seen in half a century.

Air quality in most of the region sank to “dangerous” levels, and experts calling the event a “Godzilla dust cloud” warned people to stay indoors and use air filters if they have one.

“This is the most significant event in the last 50 years,” said Pablo Méndez Lázaro, an environmental health specialist at the University of Puerto Rico. “Conditions are dangerous on many Caribbean islands.”

Many health professionals have been concerned about fighting respiratory ailments related to COVID-19. Lázaro, who is working with NASA to develop a warning system for the arrival of Saharan dust, said the concentration has been so high in recent days that it could even have a negative impact on healthy people.

Extremely cloudy conditions and limited visibility have been reported from Antigua to Trinidad and Tobago. The event is expected to last until late Tuesday. Some people posted pictures of themselves on social media wearing double masks to fend off the coronarivus and dust, while others joked that the Caribbean looked like it had received yellow filter film treatment.

José Alamo, a meteorologist for the US National Weather Service in San Juan, Puerto Rico, said the worst days for the US territory would be Monday and Tuesday when the cloud migrates towards the US southeast coast. The main international airport in San Juan reported only 8 kilometers of visibility.

The mass of extremely dry and dusty air known as the Sahara Air Layer forms over the Sahara and moves across the North Atlantic every three to five days from late spring to early autumn. According to the US, it peaks in National Oceanic and Atmospheric Administration in late June to mid-August. It can occupy a layer about two miles thick in the atmosphere, the agency said.

The Alamo said a small tropical wave towards the Caribbean should ease conditions through Thursday.

MIAMI (AP) – The US National Hurricane Center says Tropical Storm Dolly has formed over the North Atlantic but is expected to disperse later in the week.

The storm’s maximum sustained winds on Tuesday are near 45 miles per hour, but a weakening is expected in the next day or two as Dolly moves across colder waters.

Forecasters say the storm is expected to turn into a post-tropical storm on Wednesday and then resolve by early Thursday.

As of Tuesday afternoon, Dolly was centered about 665 miles southwest of Cape Race, Newfoundland, moving at 13 miles per hour from east to northeast. It does not pose a threat to any country.