Tropical Storm Erin: How Saharan dust could shape the system's path

ORLANDO, Fla. - Saharan dust, specifically the Saharan Air Layer (SAL), can significantly impact hurricane paths by suppressing storm development and potentially altering their trajectories. 

This dust is being pulled in by Tropical Storm Erin as it spins in the main development region of the far eastern Atlantic. That dusty air is warm and very dry, and when it wraps into a tropical system, it can act like sand in the gears — slowing its growth and keeping thunderstorms from fully organizing around the center.

Here's what we know about how the dust could shape Tropical Storm Erin's path.

Why does Saharan dust matter?

What we know:

Tropical Storm Erin is pulling in a plume of Saharan dust, which matters because a storm’s vertical structure — how tall and well-stacked it is from the surface to the upper atmosphere — plays a big role in where it goes.

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Weaker, shallower storms are steered mainly by low-level trade winds, which tend to push them on a more westward path across the tropics. Stronger, taller storms feel the influence of higher-altitude winds, which can pull them northward sooner and often bend them safely out to sea.

If Erin stays choked by Saharan dust for much of its life, it may remain on the shallow side, slipping past the northward "escape route" and instead tracking farther west — which could bring it closer to Florida early next week. The waters offshore of Florida are in the warm mid-80s, which would allow a potentially approaching system to continue strengthening before landfall.

If, however, it shakes off the dust and builds into a large, vertically deep hurricane, the odds increase for a sharp curve away from the U.S. coast.

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This tug-of-war between dust, storm strength and steering currents is one of the trickier parts of hurricane forecasting. Right now, the most likely scenario still shows Erin curving away — but a few model runs keep it on that westward lane, so it’s something we’ll be watching closely.

What is Saharan Dust?

Dig deeper:

Every summer, strong winds blow massive clouds of dust off the Sahara Desert in Africa. This is called the Saharan Air Layer, or SAL. These dust clouds ride the wind across the Atlantic Ocean, sometimes traveling more than 5,000 miles all the way to Florida.

RELATED: Saharan dust heads for Florida: What to expect

When the dust arrives, it can:

• Create hazy skies and reduce visibility
• Produce beautiful orange and pink sunrises/sunsets
• Lower air quality (especially tough for people with asthma or breathing issues)

However, the dust isn’t all bad. It’s full of minerals, such as iron, that can fertilize the ocean, especially around places like the Florida Keys. These minerals feed coral reefs and ocean plants, keeping ecosystems healthy. However, the dust may also carry bacteria, fungi and viruses from Africa. Some scientists think these tiny travelers could affect both people and plants, but research is still ongoing.

Tropical Storm Erin to become first hurricane of 2025 season

Big picture view:

Tropical Storm Erin is showing signs of strengthening as it continues to move west across the central tropical Atlantic, according to the National Hurricane Center (NHC). 

NHC says Tropical Storm Erin should move westward through early Thursday. After that time, indications are that the ridge may weaken over the western and central Atlantic, causing Erin to turn west-northwestward.

Although it's still too early to know exactly what impacts Erin might bring to the northern Leeward Islands, the Virgin Islands and Puerto Rico, the risk has increased for Erin to move closer to these islands over the weekend. 

There is an even greater uncertainty about what impacts, if any, might occur in portions of the Greater Antilles, the Bahamas, the east coast of the United States and Bermuda next week.