Tropical Storm Bret continues to develop, but it could have a hard time growing stronger after it enters the Caribbean where African dust in the air remains a threat.
The Saharan Air Layer, or the S-A-L-, is a massive migration of dust off of the African continent. It’s formed from tropical activity rolling off the landmass in the early part of the hurricane season. The dust travels high into the air and moves across the Atlantic.
The SAL is a tropical storm’s worst nightmare as the dry dust sucks the moisture from any nearby system keeping activity low during June and July, said Megan Borowsky, a meteorologist for the Florida Public Raio Emergency Network.
“The SAL can detract from development in the tropical Atlantic basin. And if there is some sort of cyclone all the way already out there, and then we have a plume of dust that somehow catches up with that disturbance, it can greatly decrease its intensity," she said. “It can serve to stabilize the atmosphere it influences temperature profiles and humidity profiles, such that we see something of a correlation between the Saharan Air Layer and decreased tropical cyclone activity."
Bret, the second named storm of the 2023 Atlantic Hurricane Season, is expected to strengthen over the next two days prior to entering the Caribbean, but it's forecast to weaken as it moves through the tropics where dry dust is high in the atmosphere, according to the National Hurricane Center.Bret is then expected to weaken and dissipate by the tail-end of the weekend.
As a result of its Caribbean migration, the SAL will not be passing over Florida. That's good news for those who are sensitive to dust, as the SAL can be hazardous to health, according to the Centers for Disease Control and Prevention. Dust particles can trigger asthma attacks and aggravate other respiratory conditions.
Borowsky said it is likely Floridians will see the SAL pass over sometime this summer. The arid air can be rough on the lungs, but it can also be really nice on the eyes. African dust can intermingle with atmospheric light to create some spectacular sunsets in the twilight hour, Borowsky said.
"You'll see halos around the sun, that's really just a circle around the sun, the way the dust kind of reflects and refracts light," she said. "You'll get very vivid sunsets and the atmospheric optics that occur from that, it's a pretty cool sight to see."
