The Atlantic hurricane season has been surprisingly quiet, confounding forecasters so far

Forecasters ‘expect a comeback’, with average peak season only days away (September 10). But their skills in that regard haven’t been too apparent so far this season, which has echoes of 2022 in terms of the first part being a good deal less active than confidently predicted, although it picked up later. Are they missing something important in their calculations? Top of the range for 2024 named storm numbers goes to Michael Mann with 27-39, which looks quite a stretch at this stage of the season.
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Never, in the 20-plus years it had been issuing outlooks, had the National Oceanic and Atmospheric Administration predicted so many tropical storms to develop in the Atlantic hurricane basin, with conditions across thousands of miles of ocean aligned perfectly, says the Philadelphia Enquirer.

“That’s the highest forecast that we’ve had,” Ken Graham, National Hurricane Center director, announced at the annual preseason media briefing in May. NOAA seconded the motion in its Aug. 7 update with a warning that the 2024 season “could rank among the busiest on record.” Every other major forecasting service was on board.

Said Philip Klotzbach, hurricane specialist at Colorado State University, whose preseason outlook and August update were in line with NOAA’s, “It seemed about as slam dunk a seasonal forecast as we’ve ever had.”

Yet, after the dissipation of Ernesto, the Atlantic basin, which includes the Gulf of Mexico and the Caribbean Sea, went dead quiet.

Some signs of awakening are evident, with the the hurricane center giving two seedlings outside chances of becoming tropical systems later in the week, but Labor Day weekend is proceeding without a tropical storm scare anywhere from the Texas to Florida to Maine coasts.

This would mark the first time in 27 years that not a single named storm, those with winds of at least 39 mph, has developed in the Atlantic between Aug. 21 and Sept. 2, said Klotzbach.

What explains the lull? “That’s still an open question,” said Matt Rosencrans, the Climate Prediction Center scientist who is NOAA’s chief long-range forecaster.

While the meteorological head-scratching proceeds and the atmosphere shows off its complexity, hurricane specialists do believe a prime suspect is the unusual behavior of the atmosphere over West Africa.

They also caution the season isn’t over. On average, about 70% of all Atlantic hurricanes have formed after Sept. 6.
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What is expected for the rest of the hurricane season
Forecasters are confident that the season will rally, perhaps in the next week.

”I think it’s too early to bail on the season just yet,” said Klotzbach.

Rosencrans said those winds that were directing African systems over cooler waters have shifted to the south, where the waters are less hostile to tropical storm development.

He expects to see activity return in September, when on average four named storms develop, three of which become hurricanes, and two of those, major hurricanes.

“There is still a lot of the season left,” he said.

Full article here.
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Image: Hurricane Dorian 2019 from the ISS [credit: Cayobo from Key West @ Wikipedia]