Latest Atlantic Hurricane Season Outlook Calls For Even More Storms, CSU Forecasters Say

What was already expected to be a busy Atlantic hurricane season has been increased a couple of ticks, according to a just-released outlook by Colorado State University.

Outlook is even busier: C​SU's tropical meteorology project team is forecasting 25 storms, 12 of which will become hurricanes and six of which will reach Category 3 status or stronger, in their latest outlook for 2024 released Tuesday morning.

T​his is an increase of two named storms, one hurricane and one major hurricane, in addition to an increase by 20 Accumulated Cyclone Energy units, from 210 to 230.

T​hat is well above the 30-year average tally for both hurricanes and storms, and also markedly above the tally of 20 storms, seven hurricanes and three Cat 3-plus hurricanes in 2023.

T​his outlook includes the first three named storms of this season from June and early July, including Hurricane Beryl.

I​s Beryl an omen of things to come? T​ypically, early-season activity has little correlation with how a hurricane season will go, but Beryl brings up several exceptions.

T​he first is its formation location in the deep tropics so early in the season. Storms in the deep tropics tend to develop during the heart of hurricane season (August to October), so Beryl's formation and rapid intensification east of the Lesser Antilles could be a signal that this part of the Atlantic is ready much earlier than usual.

S​econd, as CSU meteorologist Phil Klotzbach notes, Beryl lasted for a very long time and was quite potent: "Hurricane Beryl was an extremely impressive hurricane, generating the most ACE of any individual hurricane activity prior to 1 August on record."

Seasons with storms of this caliber were all above-average and had an average of 10 hurricanes, according to Klotzbach.

S​eason well ahead of schedule already: With Beryl (first hurricane) and Chris (third named storm) already in the record books, we're now weeks ahead of schedule. The average third tropical storm typically forms on August 3, followed by the fourth tropical storm on August 15. The first hurricane typically forms on August 11, followed by the second hurricane on August 26.

T​he two main drivers of an active season remain the same, both with increasing confidence:

1. T​he Atlantic's record warmth: Much of the Caribbean, Gulf of Mexico and tropical Atlantic remain much warmer than average as we head through the summer. If other factors are equal, the deeper and warmer ocean water is, the stronger a hurricane can become.

S​ea surface temperatures remain at record levels across the basin, according to Brian McNoldy.

T​his absurd warmth in the deep tropics helped lead Beryl to become such an early Cabo Verde storm and the earliest Category 5 on record in the Caribbean.

2. La Niña expected by the peak of this season: N​OAA's Climate Prediction Center is forecasting neutral conditions in the equatorial eastern Pacific to cool and become La Niña by the heart of this hurricane season, with a greater than 70% chance of developing.

This matters because it's one of the strongest influences on hurricane season activity.

I​n general, La Niña Atlantic hurricane seasons have less wind shear that can otherwise rip storms apart, and rising, unstable air that is more conducive for thunderstorms, the building blocks of tropical storms and hurricanes.

S​o this means instead of El Niño acting as a gentle brake on hurricane season, La Niña could instead step on the gas pedal.

W​e could "run out of names": This outlook of 25 storms implies we could exhaust the 2024 list of hurricane names.

A​ committee of the World Meteorological Organization maintains lists of names for tropical cyclones around the world. Each year, there's a list of 21 Atlantic Basin names that repeat every six years, unless one or more of them is so deadly and/or destructive that its name is retired.

S​o if we use up all names through William this year, a supplemental names list will be tapped, beginning with Adria.

O​nly two other Atlantic hurricane seasons in which names have been used have pushed beyond 21 storms.

In 2005 (28 storms) and 2020 (30), an alternate list of Greek alphabet letters was used for additional storms beyond the 21st storm. But use of the Greek alphabet was retired in 2021 due to confusion among Greek letters that sound similar (such as Zeta, Eta, Theta), especially if they were active at the same time.

W​e've already used the first three names on the list.

M​ORE ON WEATHER.COM:

-​ Things To Expect From Hurricane Season In July

-​ What Is La Niña?

-​ From Strong El Niño To La Niña: How Past Seasons Have Turned Out

-​ What The Cone of Uncertainty Means, And What It Doesn't