'Godzilla' Sahara Dust Cloud Update: Second Wave Set to Reach Gulf Coast

A second wave of Saharan dust is set to reach the U.S. Gulf Coast on Tuesday, causing a repeat of the conditions seen across large parts of the country over the past week.

The "godzilla" dust plume that arrived in the United States after affecting much of the Caribbean brought hazy skies, reduced air quality and vivid sunrises and sunsets to many areas.

In fact, some sections of the plume—which was described as the "most significant" in 50 years by Pablo Méndez Lázaro, an environmental health specialist at the University of Puerto Rico—are still lingering over some limited areas of the U.S., including Minnesota and southern portions of Florida, satellite imagery shows.

According to the latest forecast models, the next wave of dust—currently located in the Caribbean—is set to arrive in the Gulf Coast on Tuesday and will linger over southeastern Texas, Louisiana and southern Mississippi until Thursday or Friday before beginning to dissipate over the course of the weekend.

Satellite images show that there is currently dust hovering in the atmosphere all the way across the tropical Atlantic, from the coast of west Africa to the Caribbean.

The latest wave of dust could lower air quality to potentially risky levels, as it did last week, The Weather Channel reported.

Over the weekend some parts of the country, including Wake County in North Carolina, recorded "unhealthy" air quality, according to Environmental Protection Agency data, meaning that even healthy people can experience adverse health effects from it.

Many more areas experienced air quality that was "unhealthy for sensitive groups," which includes people with respiratory issues, seniors and young children.

For those with respiratory conditions such as asthma or certain allergies, the dust can exacerbate symptoms. And if concentrations are high enough, even healthy people may experience nose, throat and eye irritation, as well as coughing.

Dust from the Sahara regularly makes its way over the tropical Atlantic into the Caribbean and Gulf of Mexico region every year. The phenomenon is the result of tiny particles of sand and minerals in the Sahara being lifted into a hot, dry air mass that forms in the atmosphere above the desert from late spring to early fall.

Powerful trade winds blow this air mass—known as the Saharan Air Layer—westward over the ocean every three to five days between late June and mid-August, often transporting vast quantities of dust, according to the National Oceanic and Atmospheric Administration.

While this phenomenon occurs regularly every year, the plume that affected the Caribbean and the Gulf last week was "an extremely unusual event," Joseph Prospero, an atmospheric scientist at the University of Miami, told Scientific American, due to its thickness.

Recent studies looking at the links between climate change and the transport have produced mixed results, so it is currently not clear whether the recent unusual plume is a "meteorological anomaly," or if such events could become more common as the world warms, Prospero said.

Nevertheless, one study published in the journal JGR: Atmospheres indicated that periods of drought in North Africa, which may occur more frequently in future, could be linked to more intense dust plumes.

"It is curious that this particular phenomenon occurs when the highest temperatures have been recorded in the northwest of Africa. It is very possible that climate change and global warming affect and increase the amount of dust that is transported throughout the planet," Prospero told Explica.