What The Great Sahara Desert Dust Cloud Means For Pennsylvania

PENNSYLVANIA — A giant cloud of dust from the Sahara Desert is moving 5,000 miles across the Atlantic Ocean to the United States and could have a small impact on the Pennsylvania area.

Officially, it's known as the Saharan Air Layer, and it's carried from the coast of Africa across the Atlantic every three to five days from spring to early fall, with its density in mid-summer, the National Oceanic and Atmospheric Administration said.

NASA models indicate that the peak of the dust will move over southern and midwestern United States from Friday through Monday, with the northernmost tip of the layer possibly touching Pennsylvania on Saturday or Sunday.

There could be enough dust in the air locally to improve the colors in the sunrise and sunset as far north as parts of Pennsylvania, according to projections.

Air quality is a concern, but local residents don't need to worry, officials say. Southeastern Pennsylvania region will likely not be seeing the brunt of the event. NBC Philadelphia reports that the "cutoff line" of air quality concerns is around the Eastern Shore of Maryland.

Traditionally, it plays a crucial role in bringing vital minerals to the Amazon in South America. Dust particles rich in certain minerals coat the upper stories of the jungle and play an important role in regional ecology.

Its benefits go beyond the Amazon, however: research from the NOAA suggests that the plume stifles hurricanes in the Atlantic Ocean. And, perhaps more pertinently to Pennsylvania, the dust particles in the sky can create brilliant sunrises and sunsets.

National Weather Service officials said the layer is typically located between 5,000 and 20,000 feet above the earth's surface, propelled westward by bursts of strong winds located in the central and western Atlantic at altitudes between 6,500 and 14,500 feet. It's been a highly visible phenomenon in Texas and along the Gulf coast of the United States in previous years.

However, this year, the cloud is historically wide, it's swirling farther northwards than is typical, and it's present at sea level all the way up to 20,000 feet.

As of Friday, it's causing extremely hazy skies in the Caribbean, and much of the southern United States will see the dust coating cars and outdoor surfaces over the coming days. It could present a significant threat to air quality there, especially for sensitive populations.