Weather Words: Saharan Air Layer
It's wild to think that dust from an African desert can not only impact everything from our air quality to sunsets in the U.S., but also suppress hurricane activity across the Atlantic and Gulf.
It's called the Saharan Air Layer (SAL) and you'll hear meteorologists talk about it quite frequently during hurricane season. SAL is a mass of extremely dry, dusty air that forms over the Sahara Desert and travels westward over the tropical Atlantic Ocean, usually during the late spring through early fall.
The SAL can extend from about 5,000 to 20,000 feet in altitude and stretch across thousands of miles. It's often carried by strong easterly winds known as the African Easterly Jet, which acts like an atmospheric conveyor belt transporting the dust-laden air far from its desert origins.
One of the most striking effects of the Saharan Air Layer is the visible dust it carries across the ocean and sometimes even into the Americas, including the Caribbean and southern U.S. states like Texas and Florida. This dust can lead to hazy skies, vibrant sunrises and sunsets, and degraded air quality.
The most significant role this dusty air can play is its ability to suppress tropical systems. The dry air, strong winds, and warm temperatures hinder the development of tropical storms and hurricanes by limiting thunderstorm formation and creating wind shear. This 'tears apart' tropical systems, so that they don't have much of a fighting chance when faced with the warm, desert dust.
Jennifer Gray is a weather and climate writer for weather.com. She has been covering some of the world's biggest weather and climate stories for the last two decades.
Try Our AI Features
Explore what Daily8 AI can do for you:
Comments
No comments yet...
Related Articles
Yahoo
a day ago
- Yahoo
On This Date: Weather Forecast Plays Role In Shaping History Of D-Day Invasion
Weather forecasting played a pivotal role in the World War II D-Day invasion 81 years ago in an era when meteorologists had access to sparse amounts of data, including no satellite observations. Very specific conditions were needed for D-Day to happen including a full moon, low tides, light winds and calm seas. The full moon and low tide conditions lined up with June 4, 5 and 6, 1944, so it was a matter if weather conditions would cooperate with one of those specific days. The operation was planned for June 5, but it was postponed by a prediction for poor weather conditions based on observations taken in western Ireland on June 3, according to the Royal Meteorological Society. That forecast came to fruition with rough seas and winds of 25-30 mph in the English Channel on June 5. Forecasters noted June 6 could be a window of opportunity to launch the operation based on rising barometric pressure, or higher pressure, reported on a ship 600 miles west of Ireland on June 4. Weather conditions weren't perfect for D-Day on June 6 since winds were higher and clouds thicker than what would be considered optimal, but they were good enough to allow Allied forces to land in northern France, setting the stage for a defeat of Nazi Germany. Had conditions not cooperated, the entire operation would have to be delayed for a couple of weeks. Chris Dolce has been a senior digital meteorologist with for nearly 15 years after beginning his career with The Weather Channel in the early 2000s.
Yahoo
2 days ago
- Yahoo
Saharan Dust makes its way towards the United States; Will the Triad be impacted?
(WGHP) – A plume of dust from the Sahara desert has been traveling across the Atlantic Ocean making its way to the United States over the last few days. NOAA's GOES-19 satellite has been tracking Saharan dust thousands of miles across the Atlantic from May 28 through June 2. It's common to see plumes of dust from the Saharan desert cross the Atlantic. Typically, the dust gets 'kicked up' into the atmosphere over the Sahara in the late spring, summer and early fall as monsoon season gets started just south of the Saharan desert. The peak of the Saharan dust season is in late June to mid-August, just before the peak of hurricane season, which occurs from mid-August through mid-October. One reason the Triad didn't see high impacts from the most recent plume of dust is due to the weather pattern over our area of the country. The coastal low-pressure system that is bringing rain to the Piedmont Triad on Thursday is helping to keep the dust south of us, creating a bigger impact for those to our south, like Florida and even as far west as Texas. Helene's impact on transportation in western North Carolina details in new report Saharan dust is nothing new. It happens every year around this time. When storms form just south of the Sahara Desert in the Sahel region of Africa, dry, dusty air from the Sahara Desert is kicked up into the atmosphere. This dust can collect in the atmosphere about 5,000 to 20,000 feet above the desert in a 2.5-mile-thick layer known as the Saharan Air Layer. Well, in that layer above the surface are the trade winds, also known as the Harmattan wind. The Harmattan wind sends the dust into the African Easterly Jet that blows from the West Coast of Africa to the United States and carries the dust thousands of miles across the ocean. As that dust moves over the Atlantic, it suppresses tropical cyclone development. The suppression of tropical development is due to the dry, strong winds associated with the Saharan dust, and it 'chokes out' any moisture of tropical cyclones that try to develop. Tropical cyclones need warm, moist air, and the dryness of the dust can cut off the supply of warm, moist air and limit tropical cyclone development in the Atlantic as the dust moves across the ocean. While suppressing tropical cyclone development is one of the main ways that Saharan dust impacts weather conditions, it can also have effects across the United States once it arrives. A few of the impacts include lowered air quality, lowered visibility or haziness and more vibrant sunrises or sunsets. Saharan dust particles are very tiny, and, when sun filters through the particles, it scatters the sunlight even more and allows longer wavelength colors like oranges and reds to reach through and be more intense. The result is more vibrant sunrises and sunsets. However, during the day, the dust makes the sky appear hazy and lowers our typical clear visibility of light blue dust particles in the atmosphere also impact our air quality, so those with any respiratory issues will typically be impacted more when the dust has made its way across the Atlantic. The Saharan dust season has just begun and we'll likely see several more rounds of it as we head through the next few months. The FOX8 Max Weather Team will continue to track the Saharan dust as it moves over the Atlantic and will keep you updated with when it'll arrive and what impacts we could see here at home. For more information on the West African Monsoon Season and Saharan dust, catch 'Beyond the Forecast' only available on our . Copyright 2025 Nexstar Media, Inc. All rights reserved. This material may not be published, broadcast, rewritten, or redistributed.
Yahoo
2 days ago
- Yahoo
False alarms, beneficial rain and a dusty start to Florida storm season
Happy hurricane season! Clearly, many of you left several gallons of distilled water and a 96-pack of Kirkland Signature AAA batteries out in a windowless interior room on Hurricane Season Eve to appease the Cyclone Imp, because the 2025 hurricane season is off to an auspicious start. Call it Christmas in June: Internet rumors to the contrary, not a tropical depression will be stirring in the Gulf and Caribbean for another week or more. ➤ Track all active storms ➤ Weather alerts via text: Sign up to get updates about current storms and weather events by location The minimal activity in the Tropics today is actually beneficial. On the fifth day of hurricane season, the typical gift is disorganized moisture from the south (or for those observing the traditional bird-based gift calendar, five awkward teenage geese), and that's just what we are seeing out there now. An upper-level low over the eastern Gulf has been interacting with an old, stalled-out frontal boundary this week, enhancing rainfall over the Florida peninsula. As of Wednesday afternoon, rainfall totals have been two to four inches in South Florida and half an inch to an inch in Central Florida. With much of the southern half of the state in moderate to extreme drought, this precipitation is a helpful kick-start to the wet season. For the next day or two, Florida will continue to be wreathed in above-normal thunderstorm coverage as the old front drifts north. Rain chances diminish on Thursday in South Florida and Friday in North Florida as a weak area of low pressure develops in the Carolinas. If the low were to form over water, it would have a fighting chance of tropical or subtropical development, but given the trend towards more inland formation, don't expect a named or numbered system out of this one. The coastal Carolinas will dry out by late Friday as the low scoots northeast and out-to-sea. Otherwise, the rest of the Tropical Atlantic is devoid of thunderstorm activity, nestled beneath a thick, festive layer of African dust. In the first half of June, the Ghosts of Hurricane Seasons Past tell us that the most common locations for tropical storm development are the northwestern Caribbean and eastern Gulf, with something forming between June 1-15 once every three years or so. This year, upper-level winds are likely to remain more favorable for tropical development on the Eastern Pacific side of Central America rather in the Gulf or Caribbean, for at least the next 10 days. Thus, none of the reputable forecast models are showing a realistic chance of anything tropical forming on the Atlantic side of Central America through mid-month. Except the GFS. The American model is adamant that a Caribbean tropical storm will spin up in 10 to 12 days, then move generally northward. While some runs have shown an alarmingly strong hurricane, there is no chance of that happening for numerous reasons. First, only three June major hurricanes have occurred in the last 125 years, and projections of very rare outcomes should be viewed skeptically. Second, this purported hurricane hangs out in model La-La Land around two weeks away, never getting closer to fruition. Finally, the GFS has a persistent and well-known bias for incorrectly predicting development in the Caribbean at this specific time of year. All told, while something could eventually spin up in two or three weeks, the GFS' frequent false alarms should be disregarded. To make a broader point, anybody that presents GFS fantasy hurricanes as a realistic possibility is not a reputable source of weather information. Hurricane season has gotten too commercial, and there are many bad actors out there trying to profit from scaring people — if something is free, the product is you. My philosophy is that reality is plenty frightening, which is why I don't talk about extreme, unrealistic scenarios like what the GFS has been showing. Bottom line, don't be naughty and share the day 15 GFS on social media, or the Cyclone Imp will target your house with an eyewall mesovortex. Like the holidays, hurricane season tends to surface the same tired debates: Should Category 6 be added to the Saffir-Simpson Scale? Is Die Hard a hurricane season movie? Should there be a Die Hard 6? Beyond the noise, all I want for hurricane season is you to be prepared to react when the serious threats inevitably roll in. That means not sweating the small stuff, and a big part of my job is to help you avoid doing just that. Christmas may last but twelve days, but hurricane season is a hefty 183: that means whether engaging in bird gifting or assessing hurricane risks, you need to pace yourself or you'll have a real mess on your hands. So trim your trees, and keep watching the skies. Dr. Ryan Truchelut is chief meteorologist at WeatherTiger, a Tallahassee company providing forensic meteorology expert witness services and agricultural and hurricane forecasting subscriptions. For more information, visit or get in touch at ryan@ This article originally appeared on Tallahassee Democrat: Florida hurricane season forecast: Rain, Saharan dust, false alarms
