It’s not quite hurricane season yet, but AccuWeather is already sounding the alarm bells as it warns we could be seeing the signs of a tropical storm that could spin up later this month.
The Central American Gyre is the name of a broad area of slow-spinning low pressure that forms seasonally over the eastern Pacific Ocean and overlapping with the western Caribbean Sea.
AccuWeather says that the Central American Gyre could form around the middle of May, potentially laying the groundwork for a tropical depression or storm to develop.
“We’re coming out of the winter season, so we want people to start transitioning their mindset into tropical mode as we headed to the end of May, because there could be something lurking down there in the middle to late portions of the month,” said AccuWeather Lead Hurricane Expert Alex DaSilva.
“At the very least, a wetter pattern down across Central America and then up into the Western Caribbean is expected,” DaSilva added.
The presence of the Central American Gyre alone isn’t a concrete indicator of an impending tropical storm, but it does create conditions more conducive to their development.
Here’s what we know so far.
What is the Central American Gyre?
The Central American Gyre isn’t a single entity. These gyres are “large, closed, cyclonic circulations that occur during the rainy season,” according to the Oceanic and Atmospheric Research (OAR) at the National Oceanic and Atmospheric Administration.
You can almost think of these as massive tropical cyclones that sprawl for hundreds of miles. They lack the power and mobility of typical tropical cyclones. Instead, these long-lasting gyres move slowly, produce weak surface winds, and have the potential to dump buckets of rain across Central America, Jamaica, Cuba and sometimes even South Florida, according to AccuWeather.
Weather Underground meteorologist Bob Henson noted in 202 that “as smaller-scale vortexes spin around the gyre, there’s always the chance that one or more will consolidate into a tropical cyclone and eventually break away from the gyre.”
How likely is a Central American Gyre to form?
AccuWeather explains that the gyre’s formation is likely dependent on the strength of a mid-May jet stream.
“Essentially, what’s happening is we’re going to be getting a dip in the jet stream to come down into the southeastern United States during the middle of May,” DaSilva explained.
If the jet stream is strong enough to reach the Caribbean Sea, it could give the gyre just enough of a push to get it spinning.
DaSilva explained that disruptive winds known as wind shear could be low in mid-May, reducing the strength required for the jet stream to penetrate farther south.
Could Florida be impacted if a tropical storm forms before hurricane season?
It’s hard to deal with absolutes this far out. Based on current data, AccuWeather says it’s likely that a possible tropical depression or storm would track northeastward but veer toward the North Atlantic.
“Given the pattern, I think the most likely is it would just cross, cross over Jamaica, Cuba, and then head out to sea,” DaSilva said. “Right now, it does not look like it would be heading toward the United States.”
May is historically the most common month for tropical systems to develop outside of hurricane season
In recent years, a May tropical system is actually the trend. Since 2015, there were only four years when a tropical system didn’t develop in May, according to AccuWeather.
Warmer sea surface temperatures in the Atlantic and the Caribbean are part of the reason, but AccuWeather points to slow-moving cold fronts and jet streams as lesser-known culprits.
The most recent May tropical storm was Bertha, which made landfall in South Carolina just two weeks after Tropical Storm Arthur grazed the North Carolina coast in 2020.
2025 Atlantic hurricane season predictions
The CSU’s prediction for the 2025 Atlantic hurricane season proposes a slightly above-normal number of storms. Here’s a look and how the numbers compare to an average season.
This article originally appeared on Pensacola News Journal: Central American Gyre could lay groundwork for a tropical system before hurricane season
Reporting by Brandon Girod, Pensacola News Journal / Pensacola News Journal
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