Retrospective on 2024 Atlantic hurricane season 

By Theresa Barosh | June 2025

The Atlantic Ocean was unusually quiet during the typical peak hurricane season last year. It looked like Colorado State University’s 2024 hurricane season forecast had overestimated with their highest prediction yet. 

Then, the season turned around with the most late-season activity ever recorded.  

In total between July and October, the 2024 season produced 18 named storms. With the 2025 season starting, CSU experts reflect on the last season and prepare as this year’s Atlantic hurricane season begins. So far, the 2025 season has started off quietly, similarly to the previous season.  

Colorado State University researchers predicted 11 hurricanes for the 2024 Atlantic season, a record-breaking prediction after nearly three decades of providing forecasts. While the team overpredicted the amount of named storm activity, the forecasts for hurricanes and major hurricanes were quite accurate. The team predicted another active 2025 season, with 17 named storms and nine hurricanes in the upcoming months. Department of Atmospheric Science researchers in the Tropical Cyclones, Radar, Atmospheric Modeling, and Software team publish their report annually in early April. Philip Klotzbach served as the first author on the report both years.  

Researchers at CSU’s Cooperative Institute for Research in the Atmosphere collaborate with the forecast team.  

“Our Tropical Weather and Climate team works closely with CIRA throughout the year to advance our understanding of tropical cyclones and to use that understanding to improve forecasts at different lead times,” said Professor Michael Bell, part of the forecast team. “Much of our collaboration with CIRA involves the development of forecast products for the National Hurricane Center that are used in day-to-day prediction of specific hurricanes.” 

CIRA researcher Kate Musgrave specializes in predictions closer to an event, within days or hours. Musgrave reflected on Hurricane Helene and Hurricane Milton from the 2024 season. 

“We had some very unfortunate landfall positions with storms developing in the Caribbean and the Gulf” said Musgrave, “Unfortunately when they develop there, they’re going to hit land somewhere most of the time. It’s very difficult to get out of that area without hitting something.” 

Warm ocean surface temperatures combined with a high probability of La Niña conditions to drive the 2024 forecast. Researchers also anticipate above-average water temperatures across most of the tropical Atlantic for the peak of this year’s 2025 hurricane season. Hotter oceans are well understood to lead to more hurricanes, and ocean surface temperatures have reached a record high according to the National Oceanic and Atmospheric Administration. La Niña impacts wind patterns to favor storms forming in the Atlantic, while El Niño conditions tend to inhibit storm development. 

“In recent years the surface temperatures in the mid-Atlantic have been incredibly warm,” said Musgrave. “So warm that they’re actually overriding some of our common beliefs, like El Niño serving as an inhibitor because the 2023 season was extremely active during an El Niño.” 

Reflections on the 2024 Season 

Two Category 5 hurricanes, Beryl and Milton, had winds at 157 mph or higher. Category 5 storms can uproot trees, ruin power poles and destroy buildings. Hurricane categories range from Category 1, with winds from 74 to 95 mph, up to Category 5. However, wind speeds are not the only factor that determines how destructive a storm may be said Klotzbach. Rainfall and storm surge, water level rise, can also lead to damage. 

Hurricane Beryl became the earliest recorded Category 5 hurricane on July 2.  

“Hurricane Beryl was an impressive storm,” said CIRA researcher Dakota Smith, “and set an ominous tone for the season.” 

Then, skepticism about the forecast set in as the Atlantic Ocean got unusually quiet between August and September. In mid-September, activity picked up as Francine formed east of Mexico. Francine made landfall in Louisiana, on September 11 as a Category 2 storm. Hurricane Helene hit on September 24 after forming in the western Carribean Sea. Helene rapidly intensified into a Category 4 storm, with winds of 140 mph.  

“This storm was really neat to watch evolve. Hurricane Helene came along and added more moisture after an initial system went through,” said Smith, “It added up to an absurd amount of rain. This event upended thousands of lives across the region.” 

Eleven tropical storms followed, including Hurricane Milton which made landfall in Florida on October 9. Milton had decreased from a Category 5 to a Category 3 storm by the time it made landfall. Over 40 tornadoes were reported in Florida on October 9.  

“We started the season off with a bang and ended in similar fashion,” said Smith, “Milton was one for the record books.”  

Why Does CSU Forecast So Early? 

The CSU forecast team starts reporting predictions months before the Atlantic Hurricane season begins. These seasonal forecasts were developed by the late William M. Gray, a faculty member in the CSU Department of Atmospheric Science. The model used to build the forecast has been improved over decades by many contributors, including CSU alums.  

Researchers point out that it only takes one hurricane making landfall to have a serious impact. 

“Part of the reason we issue the forecast in April is to get people thinking about preparations for the upcoming season,” said Bell. “Residents near the coast should prepare thoroughly before the season to make sure they restock their supplies, know their evacuation routes, and have plans in place for when a storm is forecast to impact their area.”  

With populations along the east coast growing quickly, Musgrave said that it is important to re-visit evacuation plans regularly. When people evacuate, it can also impact those inland, especially near evacuation centers. The outcomes of storms can be felt across the nation. 

“We’re all interconnected nowadays: a blizzard in the northeast and all of a sudden you can’t catch your flight because everything’s been shut down and delayed, and that cascades through the country,” said Musgrave. “A hurricane hitting Houston and all of a sudden we can’t get gasoline at cheap prices.” 

What is needed: Continued support for hurricane researchers because hurricane forecasters need the information and support to continue to save lives.