First Bouts Of Saharan Dust Are Reaching Caribbean,Florida. Here's What To Know About Its Impact On Hurricane Season And Your Health

The dust from Africa spreads across the Atlantic during the early part of each hurricane season. Some of it has now reached Florida.

18 hours ago

Cone of Uncertainty:What It Actually Means

The first big surge of Saharan dust from Africa has been sweeping through the Atlantic and Caribbean the past few days and has now spread into Florida.

Here's what you need to know about this dust:

In Brief:Saharan dust travels thousands of miles from Africa to the Americas each spring and 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 Depth:More formally,it is 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. 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 as they move westward from Africa to the Pacific.

Timing The Dust

The analysis below shows the highest concentration of dust in brown located from the eastern Gulf of Mexico to Florida and off the Southeast coast.

Drier air in association with this batch of dust will lead to a decrease in shower and thunderstorm activity the next few days,especially in the southern half of Florida. It will also make for hazy skies and glowing orange sunrises and sunsets,where the sky is not too cloudy.

What The Dust Can Do

1. Drier air can squash thunderstorms and tropical systems:One of the reasons we don't start watching the stretch between Africa and the Caribbean for tropical activity in June and July is because of this dust. The dust is not only dry but also has a sinking motion in areas that it passes through. This is not favorable for thunderstorm growth. Tropical waves often have a rough time developing if they are enshrouded by the Saharan air layer.

Dust can also zap other ingredients needed for tropical development. Saharan air can reflect sunlight before it can reach the Atlantic,slightly cooling the oceans. Stronger winds within the SAL also increase wind shear,which can either tilt or rip apart a tropical system.

But as the dust and wind shear weaken ocean warmth will peak in the late summer months. That's why the heart of the hurricane season is from late August into October,during which 82% of a hurricane season's activity usually takes place.

This same thunderstorm-squashing idea that is found in the tropics is also found when the dust gets closer to the Southeast. When dust is passing through,there is often a multiday drop in rain chances until the dust is gone. In Florida,this means there is a break in the rainy season,but that's not always good news.

This pause in sea breeze thunderstorms allows Florida's typical high temperature of 90-92 degrees to rise by a few degrees without much of a drop in surface humidity. This can make it even more uncomfortable to be outside. Be sure to take breaks and keep hydrated.

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

2. Dust can diminish air quality:When a Saharan Air Layer arrives,you'll typically notice hazier skies than usual for a summer day. This is your first signal that you may want to check the air quality. 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.

If you are susceptible to breathing issues,you may want to limit your time outdoors or take a mask with you if you have to leave your home.

3. Particles can make for more beautiful sunrises and sunsets:If the air quality in your area isn't too bad,head outside early or late in the day. If you know that dust is overhead,you'll probably notice that your sunrises and sunsets appear more orange or reddish. This can make for some spectacular photos.

MORE ON WEATHER.COM:

Jonathan Belles has been a digital meteorologist for www.weathernow24.com for 9 years and also assists in the production of videos for Weather Now 24 en español. His favorite weather is tropical weather,but also enjoys covering high-impact weather and news stories and winter storms. He's a two-time graduate of Florida State University and a proud graduate of St. Petersburg College.