May 23, 2024 - Energy & Environment

NOAA forecasts extraordinarily busy Atlantic hurricane season

A map of the Atlantic ocean showing sea surface temperature anomalies as of May 7-21, 2024
Data: NOAA; Map: Erin Davis/Axios Visuals

The 2024 Atlantic hurricane season features an unprecedented combination of air and ocean conditions, and is likely to be extremely active, according to the U.S. government's official seasonal outlook released this morning.

Why it matters: Hurricanes are nature's largest and most expensive storms, and the odds of a U.S. landfall during an above average season may be generally higher this year.

  • "This season is looking to be an extraordinary one in a number of ways," said National Oceanic and Atmospheric Administration administrator Rick Spinrad in a press conference.

By the numbers: The NOAA is forecasting the season will bring 85% odds of an above normal season, with 17–25 named storms of tropical storm intensity or greater, eight to 13 of which will become hurricanes, and four to seven major hurricanes of Category 3 or greater.

  • This is the most aggressive hurricane season outlook that NOAA has ever issued for its May outlook, Spinrad said.
  • The numbers are well above the 1991–2020 average of 14 named storms, seven hurricanes and three major hurricanes each season.
  • NOAA is projecting just a 5% chance of a below average season.

Threat level: This season will officially start on June 1 in unparalleled territory.

  • There are record to near-record warm ocean waters in every part of the Atlantic, from the Caribbean to the "Main Development Region," where many of the fiercest storms with the highest odds of affecting the Leeward Islands and U.S. get their start, all the way to more northern latitudes.

Stunning stat: The Caribbean's current average ocean temperature is currently higher than the 1991–2020 typical peak for an entire season, whereas the Main Development Region's ocean heat content is at Aug. 10 levels.

  • The Gulf of Mexico is also warmer than average.

How it works: Warm water is hurricane fuel. There are few signs that a significant cool down will take place between now and the heart of the season in August and September.

  • However, some portions of the Atlantic may be knocked out of record territory during the season.

The big picture: At the same time, in the equatorial tropical Pacific Ocean, a transition from a strong El Niño to a La Niña event is underway. La Niña typically reduces upper level winds over the tropical Atlantic, which can weaken tropical storms and hurricanes.

  • According to Michael Lowry, a hurricane and storm surge specialist for WPLG Local 10 in Miami, La Niña can allow storms to form closer to the East Coast and threaten land, given the relaxed wind shear.
  • "The switch from a potent El Niño in 2023 to La Niña conditions by the 2024 hurricane season would not only reduce storm-busting wind shear in the Atlantic, it could also lessen that protection closer to land areas, including the mainland U.S.," Lowry told Axios via email.
  • "While seasonal hurricane forecasts can't tell us when or where a storm might strike, the record warm waters through the Caribbean and Gulf combined with a potential La Niña does stack the deck in favor of development farther west in the Atlantic this year and potentially closer to land areas."

Yes, but: There are factors that could thwart nascent tropical storms and hurricanes even with extremely warm waters present.

  • These include the presence of dry air in mid levels of the atmosphere, and Sahara dust blowing across the Atlantic from western Africa.

In addition, while the oceans would support intense storms, clusters of thunderstorms, or "seeds" of tropical storms, are required in order to generate hurricanes.

  • These could be missing in action this season, though computer models do not suggest this will be the case.

Context: This season comes as numerous studies point to climate change's increasingly clear influence on hurricanes.

The bottom line: There are plenty of critics of seasonal hurricane outlooks who say they do not provide people with actionable information.

  • But Lowry urged people to prepare for this season as they would for any other, and to take advantage of state tax holidays, which Florida has on June 1, for example, to stock up on supplies.

Go deeper: As El Niño fades, hurricane-boosting La Niña looms large

Go deeper