Saharan Dust Could Spread to Caribbean, Gulf of Mexico and US Into Next Week – The Weather Channel

An outbreak of dust from the Sahara Desert could spread to the Caribbean by this weekend, and it might reach the Gulf of Mexico and parts of the United States next week.

Known as the Saharan Air Layer (SAL), this dry dust plume commonly forms from late spring through early fall and moves into the tropical Atlantic Ocean every three to five days, according to NOAA's Hurricane Research Division (HRD).

You can see in this animation from Tuesday how an expansive area of dust has moved from Africa to the central and eastern tropical Atlantic Ocean.

Saharan dust tracks as far west as the Caribbean Sea, Florida and the Gulf of Mexico each year a 5,000-mile-long journey. The dust particles can contribute to hazy skies at times during the summer in the Caribbean Islands, South Florida, the Florida Keys and the U.S. Gulf Coast. The dust can also cause toxic algal blooms in the Gulf of Mexico, according to NASA.

The HRD says the Saharan Air Layer is typically located between 5,000 and 20,000 feet above the Earth's surface. It is transported westward by bursts of strong winds and tropical waves located in the central and western Atlantic Ocean at altitudes between 6,500 and 14,500 feet.

The National Weather Service in Puerto Rico noted on Monday that a weak Saharan Air Layer was creating hazy skies and providing dry air to their area early in the week.

By later this week and especially this weekend, a more concentrated area of dust is expected to spread toward the Caribbean. You can see this in the forecast below from NASA's GEOS-5 model, which shows an expansive area of dust moving into the Caribbean by Sunday.

That dust might ultimately reach the Gulf of Mexico and parts of the United States by early next week.

The National Weather Service in Houston mentioned that their area could see red skies at sunrise and sunset next week because of the dust. This could also happen on other parts of the U.S. Gulf Coast, depending on the exact path of the dust and how much of it spreads that far west.

Given the SAL is most common during hurricane season, research has been done on how it can affect the development of tropical storms and hurricanes. According to NOAA, some of the potential impacts to tropical development caused by the SAL include:

- The dry air can create downdrafts (sinking air) around tropical storms and hurricanes, which may result in the weakening of tropical cyclones.

- Strong winds associated with the SAL can contribute to increased vertical wind shear the change in wind speed with height which makes the environment hostile for tropical cyclone development.

- The role dust plays in tropical storm and hurricane intensity is not known. However, some research says it might impact cloud formation.

The early part of hurricane season is typically quiet in the tropical Atlantic. But this outbreak of dust along with unfavorable upper-level winds will likely put a lid on any significant tropical development in the near-term future.

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Saharan Dust Could Spread to Caribbean, Gulf of Mexico and US Into Next Week - The Weather Channel