Florida has made it past the statistical peak of hurricane season with barely a ripple in the tropics, and Andrew Wulfeck, a meteorologist with the Florida Public Radio Emergency Network, says a mix of atmospheric factors is behind the lull.
Wulfeck said a strengthening El Niño over the Pacific is one of the biggest reasons tropical systems have struggled to develop this year.
"You have probably heard about growing El Niño over the Pacific," Wulfeck said. "And so what that does is it really increases that shear over the Atlantic Basin. So that includes the Gulf, the Caribbean, and of course the Atlantic Ocean."
Wind shear — changes in wind speed and direction with height — can tear apart developing storms before they have a chance to organize.
Persistent dry air across the basin has compounded the problem, Wulfeck said.
"There's been a lot of dry air over the Atlantic, and we have really seen dry air become an increasing problem for tropical cyclones over the last several years," he said. "So when you combine all these factors together, Atlantic has been tepid, to put it at best, in terms of tropical activity."
Despite the quiet stretch, Wulfeck cautioned against complacency. The Atlantic hurricane season officially runs through November 30th and we just passed the statistical September 10th peak.
"Just over 60% of all activity occurs after the September 10th date," Wulfeck said. "So we still have a long way to go in terms of the season, with September and October still being some of the peak months."
Wulfeck said residents could reasonably start to relax once October winds down, though he noted hurricanes have struck Florida as late as November before. He pointed to Hurricane Nicole, which came ashore along Florida's east coast in November 2022, and Hurricane Kate, which struck the Panhandle near Mexico Beach in November 1985, days before Thanksgiving.
"But once we get into the October time period, is when we can start to give the all clear," he said.
In as far as the Saharan dust, Wulfeck described a mass of dry air that forms off the coast of Africa and moves westward across the Atlantic, typically peaking in July and early August.
"It's during the down years where it kind of goes on and on and on and never really seems to end," Wulfeck said. "That's one of these years where we're seeing these big plumes off Africa work their way westward, and they just put a cap on all tropical activity across the Atlantic Basin."
Wulfeck said the dust layer strips moisture out of the atmosphere, which starves storms of the fuel they need to form.
"If you think of it as a column, it has about 50% less moisture in it where there is this Saharan dust air layer," he said. "Usually during an active year, it really subsides during late August, September and October. So you really don't hear about the Saharan air layer, or what's called the SAL."
"This year it has remained active. So the SAL has been relatively thick, and once again that's put a cap on any thunderstorms," Wulfeck said. "Once you do that, you really need thunderstorms for any type of tropical cyclone to form."