LOS ANGELES - Clear, blue skies are turning brown.
A historic Saharan dust plume that blanketed the Caribbean over the weekend is now closing in on the Gulf Coast.
The densest plume of dust developed off Western Africa and has traveled nearly 5,000 miles across the Atlantic Ocean.
According to the National Oceanic & Atmospheric Administration, the plume of dusty air reached the United States Thursday morning, bringing dust particles to the deep Southern United States.
Frank Marks, director of the Hurricane Resarch Divsion at NOAA's Atlantic Oceanagraphic and Meteorological Laboratory, says that these plumes are frequent in the summer, especially in June and July, and take about 10-12 days to cross the Atlantic.
"The one we had was probably the most intense on record so far, and they've been keeping records of these dust outbreaks probably about 70 years," Marks said of the current dust plume.
This dust is expected to stretch from Florida to the Gulf Coast to as far west as Texas, before turning back eastward.
This is not likely to cause major deterioration in the air quality for the U.S. at large, since the dust is elevated and concentrations are continually and gradually disippaiting. Additionallly, water vapor present in the the South will wash away dust particles.
According to Sonoma Tech Meteorologist Jeff Beamish, Baton Rouge's air quality reached unhealthy levels for sensitve groups on Thursday.
According to Beamish, model runs show that the dust plume is predicted to cause impacts for Texas and Louisiana Thursday, potentially spreading into the central and eastern U.S. by Saturday.
A lot of the numerical models predict that the track will head toward Alabama and Lousiana, before moving northward into Georgia, and maybe as far north as North Carolina, Marks said.
But the dust plume has the potential for beauty, as well. Louisiana and Alabama residents can get out their cameras, because it may produce some gorgeous sunsets Thursday evening.
A Saharan Air Layer (or SAL) is a mass of dry and dusty air, which forms over the Sahara Desert and moves over the North Atlantic.
According to NOAA, this dry layer of air usually travels about one mile above the ocean surface. The extremely dry air can inhibit tropical cyclones and activity.
Over the weekend, the Saharan dust reached the Caribbean.
NOAA shared a satellite image of the dust plume. “This particular plume has reportedly spread over the Caribbean, reducing visibility in some areas to five miles.”
Beamish wrote, “The Saharan air layer’s definitely not a new phenomenon. It happens yearly, with varying amounts of dust traversing the Atlantic basin.”
A second round of dust is expected to cross the U.S. This contentrated dust plume will take about 7-8 days to arrive to the U.S., just in time for the fourth of July weekend. However, it's predicted to be less intense than the current plume.