By Brooke Rogers | CBS 11 News|

DALLAS (CBSDFW.COM) – Dallas’ famous skyline was hard to find Monday morning from Chopper 11.

A thick haze hung over the metro area and beyond all weekend – a phenomenon called Saharan dust. It’s dust from North Africa, more than 5,000 miles across the globe. It blew across the Atlantic, the Caribbean and the Gulf of Mexico to make life miserable for North Texas allergy sufferers.

“It’s particulate matter – 2.5 microns or smaller. So it’s considered dust, but it carries with it sometimes some environmental concerns,” says CBS 11 Meteorologist Jeff Ray.

That dust is a pollutant that affects our air quality index, according to the Texas Commission on Environmental Quality. In parts of N. Texas this weekend, the plume triggered the highest levels of this type of pollution in 20 years. Monday, the air quality index and ozone were moderate in Dallas/Ft. Worth. Ray says it’s common for Saharan dust to find its way to the Caribbean but not to North Texas.

“Circumstances have to be just right, but we will get a larger, usually a large swath of it, and this is a large area, as big as the state of Texas, that will come in and affect us for days on end,” he says.

The dust does actually have some benefits: It can prevent thunderstorms or even hurricanes from developing. Anyone with respiratory problems should avoid too much outdoor time until the dust clears. Ray says it’s on its way out, but we could have another wave based on what happens in the Gulf this week.