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Dangerous Saharan Dust Cloud May Reach U.S. Gulf Coast By Weekend

The massive plume will bring hazy sunsets — and hazardous health conditions.

The first trans-Atlantic Saharan dust cloud of 2022 is coming.

It could approach the Gulf Coast states this weekend, bringing health hazards along with hazy skies.

The enormous plume of dust referred to as a Saharan Air Layer (SAL) is made of dry air carrying dust from the Sahara Desert as it journeys cross the Atlantic Ocean. The dust makes its annual trip from May to August and can reach as far as the central United States, spiking air pollution and agitating health issues.

As of Tuesday, the dust was still over the Atlantic, with computer model simulations projecting the dust cloud will sweep across the Caribbean before it could reach the U.S. Gulf Coast.

A simulation of a massive dust plume’s passage from the Sahara to the southern U.S. (AccuWeather)

“A large batch of dust was evident on satellite photos from the start of this week and was beginning to enter the Caribbean,” said Alex Sosnowski, AccuWeather senior meteorologist. “It is possible, but not a certainty, that this dust will make the trip as far as the Gulf and south-central U.S. late this week or this weekend. Some dust is probably going to reach Florida. The biggest impact will be to make the sky appear hazy, but it can also give extra color to sunrises and sunsets.”

The hazy sunsets are similar to wildfire smoke that drifts eastward across the U.S.

There is a “pretty good” area of dust now crossing the main development region of the tropical Atlantic — and this will bring hazy skies to the eastern Caribbean during the next couple of days, according to Dan Kottlowski, AccuWeather hurricane expert. “The dust seems to dissipate with time and probably won’t be much of an issue as it moves farther west,” he said.

The European Copernicus Atmosphere Monitoring Service (CAMS) model shows the plume of dust veering more eastward, missing most of the Gulf except for parts of Florida.

“The dust will move northwest high in the atmosphere and could make for brilliant sunrises and sunsets in the Caribbean late this week and the weekend,” said Jesse Ferrell, AccuWeather senior weather editor.

“While NASA’s dust forecast model shows some dust in the skies over the western Gulf coast from Louisiana to Texas on Sunday, the Copernicus satellite model says the dust will dissipate before it reaches the United States, except for southern Florida,” he said.

The particles from the plume mostly hover about a mile above the surface in a layer about 2 to 2.5 miles thick, but the particles can pose a dangerous health risk when they fall to the ground level.

The dust particles from the Sahara that reach the U.S. tend to be too big to be inhaled. But that’s not the case for all the particles transferred in the plume, Dr. Meredith McCormack, an associate professor of medicine and medical director of pulmonary medicine at Johns Hopkins University and volunteer medical spokesperson for the American Lung Association, told AccuWeather

Fine particles of silica, along with other minerals, can irritate people’s eyes, ears, noses and throats and can even infiltrate lung tissue, aggravate sensitivities and reduce visibility, according to NASA.

“We know that generally, particulate matter has a myriad of health risks, including the increased mortality risk of worsening underlying chronic disease, like provoking asthma attacks or COPD exacerbations,” McCormack said.

Children and individuals with chronic medical conditions, such as heart or lung problems, are typically most at-risk from dust, McCormack said.

In addition to the health impacts, the SAL can also stifle clouds and thunderstorms, worsening hot summer days.

A satellite image of the Saharan dust crossing the Atlantic and heading for the Gulf of Mexico. (NOAA/CIRA /RAMMB)

“A substantial amount of dust and the dry air that often accompanies it can hinder convective precipitation, such as showers and thunderstorms,” Sosnoski said. Experts say that significant amounts of dust can also inhibit tropical cyclone formation or the strengthening of an existing system.

The SAL’s characteristically dry air is one of the factors that meteorologists believe could weaken tropical cyclones and disturbances. The SAL’s air has about 50 percent less moisture than the typical tropical atmosphere, according to the National Oceanic and Atmospheric Administration.

The strong winds in the SAL can also substantially increase the vertical wind shear in and around the storm environment, potentially disrupting any forming cyclone.

However, while AccuWeather forecasters are currently monitoring for potential tropical development toward the end of the month, Sosnowski said the easterly winds kicking up could potentially help, rather than hinder, the formation of a gyre, circulating ocean currents, in the Gulf.

Produced in association with AccuWeather.

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