Biggest Dust Outbreak of the Season Blankets the Atlantic

Quiet end to June expected across the tropics

Saharan dust (hazy orange area) over the tropical Atlantic west of Africa on Sunday, June 23, 2024. The presence of pillow-like stratocumulus clouds near the dust plume indicates dry, stable air associated with the Saharan Air Layer, extending between 5,000 and 20,000 feet high. Credit: NASA

So far the Atlantic hurricane season hasn’t thrown us any curveballs. It’s been business-as-usual for June with lots of rich tropical air getting pulled out of the Caribbean, one named tropical storm (Alberto) that formed almost to the day we’d expect our first named storm, and two close-call tropical depressions that just couldn’t make it the extra mile. Of course the impacts – from the historic South Florida flooding to the major coastal flooding south of Galveston – weren’t without consequence, but they’re what we often get in June – big, sloppy disorganized systems near the U.S. with lots of rain, especially into Florida and Texas.

After a flurry of activity last week that could just have easily ended with three tropical systems as the one that formed, the tropical Atlantic appears ready for a summer vacation this week. A major outbreak of Saharan dust – the largest of the season and the biggest outbreak since at least April – has blanketed the Atlantic as it often does this time of year.

Weekly dust cover across the tropical Atlantic for 2024 (peach color) and 2023 (rust color). 2023 saw the lowest dust cover through the Main Development Region of any hurricane season since continuous dust records began in 2002. The ongoing dust outbreak is the biggest since April and will bring the Atlantic in line with typical levels that usually peak this time of year.

Last hurricane season observed record low dust cover across the Atlantic Main Development Region and so far this summer the dust plumes from northern Africa have been running well below average. This week’s dust outbreak looks to bring more seasonal levels, with dust forecast to reach all the way to the shores of South Florida and the Gulf of Mexico by the weekend.

Dust forecast through next Sunday, June 30th. Credit: Weathermodels.com

Despite a few robust tropical waves dotting the Atlantic this morning – disturbances that spin off Africa every three to five days that can be seedlings for storms and hurricanes – forecast models are sheepish on development through the end of the month. This can largely be attributed to the presence of still-strong upper-level winds and Saharan dust which peaks in late June and early July and tends to stifle thunderstorm growth.

Meanwhile closer to the United States the sprawling Central American Gyre responsible for Tropical Storm Alberto and its sister disturbance that moved into northern Mexico over the weekend has mostly retreated and probably won’t return in earnest again until the fall.

So for now, enjoy the respite. Once July arrives, we’ll be looking a little farther out over the Atlantic as tropical waves start to show a little more flare.