Saharan Dust Puts Hurricane Season On Pause | Weather.com
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Saharan Dust Puts Atlantic Hurricane Season On Pause

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Saharan Dust Dominates The Atlantic Basin

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Dust-laden S​aharan air surging across the Atlantic Basin will squash tropical development for the next several days after a busy start to the hurricane season.

A breather after a sprint: The National Hurricane Center doesn't expect tropical development anywhere in the Gulf of Mexico, Caribbean Sea or Atlantic Ocean for at least the next seven days.

T​hat followed a busy period from mid-June through last week with three named storms, one of which was early-season record-shattering Hurricane Beryl.

2024 Atlantic hurricane season tracks through July 15, 2024.
(Data: NOAA/NHC)

A​ surge of dust: One reason for the calmer tropics is a massive push of dusty air westward across the Atlantic Basin from Africa's Sahara, known as a Saharan Air Layer (SAL).

It's currently the most Saharan dust across the Atlantic Basin in over two years, according to WPLG-TV hurricane specialist Michael Lowry.

image
Saharan Dust Analysis
(Areas in the brighter tan contours show areas of more concentrated dust in the atmosphere, in this case, originating from Africa's Sahara Desert. Clouds detected by satellite are also shown. )

You can see that in the map above as an expansive mass of tan contours extending from Africa over 1,000 miles westward into the Atlantic Ocean, as well as other patches of dust in parts of the Caribbean and the southern U.S., including Texas.

Each year, some 800 million metric tons of desert dust blow up from North Africa and become the largest source of airborne dust particles on the planet, according to NASA.

W​hy it matters: According to NOAA’s Hurricane Research Division, these SALs form from late spring through early fall and move into the tropical Atlantic every three to five days.

It typically squashes tropical development in two ways. Its thick layer of hot, dry air starves the area of deep moisture. The dust within these SALs can also reflect sunlight, slightly cooling the oceans. Each of these can limit thunderstorms, the building blocks of tropical storms and hurricanes.

Stronger winds within the SAL also increase wind shear, which can either tilt or rip apart a tropical system.

(For even more granular weather data tracking in your area, view your 15-minute details forecast in our Premium Pro experience.)

H​ow far they can go: It’s common for SALs to be pushed westward by bursts of strong winds and disturbances known as tropical waves.

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They usually reach the Caribbean Sea several times a summer. Once or twice a summer, one of these SALs makes a complete 5,000-plus mile journey as far west as the Gulf Coast, from Florida to Texas.

In fact, a June 2020 SAL not only reached the Gulf Coast, but penetrated well inland as far as eastern Nebraska.

W​hat you'll notice: When a Saharan air layer arrives, you'll typically notice hazier skies and less thundershower activity than usual for a summer day. That increased haze can lead to some brilliant, colorful sunrises and sunsets.

Health experts say the dust particles could trigger symptoms similar to springtime allergies or cause respiratory irritation for people with conditions like asthma or emphysema.

(Further beef up your forecast with our detailed, hour-by-hour breakdown for the next 8 days – only available on our Premium Pro experience.)

N​o predictor for the season: According to NOAA’s HRD, SAL activity usually hits a peak from late June through mid-August. That’s one reason why the first few months of the hurricane season are usually more quiet. The SAL's suppressing effect acts as a brake on early-season activity.

But as the SALs and wind shear weaken, and ocean warmth reaches its peak, conditions become much more favorable for hurricane formation. That's why the heart of the hurricane season is from later August into October, during which 82 percent of a hurricane season's activity usually takes place.

Average number of storms (bright red), hurricanes (maroon) and Cat. 3-plus hurricanes (darkest maroon) through an Atlantic hurricane season.
(Data: NOAA/NHC)

S​o, enjoy this lull in activity while you can. It won't last long, especially given the volatile mix of ingredients setting up this season.

M​ORE ON WEATHER.COM

-​ Hurricane Beryl Recap

-​ La Niña Still Expected To Develop

-​ Late Summer, Early Fall Temperature Outlook

Jonathan Erdman is a senior meteorologist at weather.com and has been covering national and international weather since 1996. His lifelong love of meteorology began with a close encounter with a tornado as a child in Wisconsin. He completed a Bachelor's degree in physics at the University of Wisconsin-Madison, then a Master's degree working with dual-polarization radar and lightning data at Colorado State University. Extreme and bizarre weather are his favorite topics. Reach out to him on X (formerly Twitter), Threads, Facebook and Bluesky.

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