Advertisement

Large dust plume from the Sahara Desert could briefly slow hurricane activity

The dust also will make for spectacular sunsets by the time it reaches Tampa Bay next week.
 
A plume of Saharan Dust can be seen from satellite imagery.
A plume of Saharan Dust can be seen from satellite imagery. [ National Oceanic and Atmospheric Administration ]
Published Aug. 19, 2021

A week filled with activity from tropical systems Fred, Grace and Henri could soon be followed with a quiet tropical Atlantic.

You can thank a plume of dust off the Saharan Desert for that.

The National Weather Service confirmed Thursday that a larger-than-usual plume of dust already moved off Africa’s east coast and is headed west toward Florida. Once the dust reaches the Sunshine State, which is expected to happen around Wednesday of next week, experts predict it will not only lower rain chances — it also will make for photographic sunsets that feature more hues of red and orange in the sky.

Spectacular sunsets shouldn’t be the main reason Floridians are excited, however: The plume will also suppress tropical systems from forming and strengthening as it passes across the Atlantic Ocean.

How does it do that? Rick Davis, a meteorologist at the National Weather Service’s Ruskin office, said the dust robs the moisture out of the air of potential storms. The moisture is what fuels storms, he said, meaning the dust could keep future hurricanes from ever forming.

The dust has an official name given to it by the National Oceanic and Atmospheric Administration, which calls it “Saharan Air Layer” — or just “SAL.” It’s a common phenomenon that lifts dust particles from the desert up 5,000 to 20,000 feet above the earth before moving it westward over the Atlantic.

SAL occurs mostly in the first half of hurricane season, which runs from June through November, and it usually diminishes in size by mid-August. The National Weather Service’s Ruskin office said Thursday, however, that the latest bloom is “a good size” for this time of year.

Some in Tampa Bay may remember the brief respite the Saharan Air Layer brought last June and July. That’s when a historic Saharan phenomenon created a 24-day lull of tropical tranquility in the Atlantic Ocean in the midst of the most active hurricane season in recorded history. Only one storm formed from June 10 to July 4, but it never approached land, disappearing in the North Atlantic.

That Saharan Air Layer outbreak was the “dustiest” on record, said Weather Channel meteorologist Carl Parker. It covered an area larger than the 48 contiguous states and traveled 5,000 miles from Africa to the southwestern states. While smaller in size this August, the weather service said the latest plume could yield similar results, just for a smaller period of time.

• • •

2021 Tampa Bay Times hurricane guide

IT’S STORM SEASON: Get ready and stay informed at tampabay.com/hurricane

THE TRUTH IS OUT THERE: Seven hurricane myths that need to go away

BACK-UP YOUR DATA: Protect your data, documents and photos

BUILD YOUR HURRICANE KIT: Gear up — and mask up — before the storm hits

PROTECT YOUR PETS: Here’s how to keep your pets as safe as you

NEED TO KNOW: Click here to find your evacuation zone and shelter