Hurricane season in the Atlantic Ocean spans June through November and this year was forecasted as one for the record books, thanks to several climatological features.
However, as we approach the midway point between the season, the under performance, so far, in the Atlantic basin has many questioning whether the season was over forecasted or the second half will see an "explosion" of activity.
Both the National Oceanic and Atmospheric Administration (NOAA) and Colorado State University (CSU) made their seasonal forecasts back in May and had above average, ranging from 17 to 25 tropical cyclones (named storms) for NOAA and 23 named storms for CSU.
The average number of named storms is around 14 per season. So why the extreme forecasts?
The factors that contributed to the high number of storm predictions include near-record warmth of the Atlantic Ocean water temperatures and a La Niña. The La Niña creates a cooling of the equatorial Pacific Ocean temperatures but also reduces the wind shear and Atlantic trade winds, resulting in favorable conditions for storm development.
The season began strong. Alberto formed in mid-June over the southwestern part of the Gulf of Mexico.
Next came Beryl, a long-lived storm that formed late June, south of Cabo Verde and traversed the Atlantic Ocean, intensifying into a Category 5 hurricane on July 2, becoming the earliest Category 5 hurricane on record.
Other storms that followed included Hurricane Debby and Hurricane Ernesto. Here’s a look at the 2024 hurricane season so far.
By mid-August, conditions in the Atlantic went quiet. A lull that lasted several weeks.
Early September saw the Atlantic wake up, with Francine forming on Sept. 9 in the southwestern Gulf of Mexico from a tropical wave that crossed the Atlantic the week prior.
The sea surface temperatures (SSTs) of the North Atlantic remained extremely warm for much of the year. However, since early June, the central equatorial Atlantic has been about 0.5 to 1.0 degrees Celsius colder than average for this time of the year.
Dubbed, “Atlantic Niña,” this phenomenon has shifted the track of the “seed” storms, or disturbances that move west off the coast of Africa into the Atlantic Ocean and typically develop into intense storms. According to NOAA, “a stronger West African Monsoon, the track of these waves has shifted north toward cooler waters and overall, less conducive conditions needed for tropical cyclone formation.”
As of early September, the cooling of the central equatorial Atlantic has weakened with tropical activity expected to increase. NOAA suggests that even in active seasons, there can be periodic lulls in activity and is still forecasting a well above-average season.
“We are just coming up on the halfway mark of the hurricane season, usually the time of peak activity,” says Dr. Frank Marks, a meteorologist in the Hurricane Research Division of NOAA/Atlantic Oceanographic and Meteorological Laboratory.
Location is key. “For the month of September into early October, the most likely place to watch for tropical cyclone development is still the central Atlantic in the Caribbean. However, there is always a possibility of a tropical cyclone developing in the Gulf of Mexico along an old front.”
Stressing that systems that form in the Gulf of Mexico are dangerous, “As they are likely to strike land in 2-3 days rather than being able to track them across the Atlantic for a week or more.”
As for whether this season will be a bust for forecasters, Dr. Marks explains it like this. “Each hurricane season is different, with different changes in the weather patterns that affect the likelihood of storms to form. You need to remember that as Mark Twain once said, ‘Climate is what you expect, but weather is what you get.’”
Unfortunately, as history has proven, it doesn’t matter the total number of storms per season because it only takes one storm to make landfall in your area and cause devastation.
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