Tropical weather experts unveiled their annual seasonal outlook for the upcoming Atlantic Hurricane Season which begins June 1: while it won’t be nearly as busy as last year’s season, it still looks like it’ll be an above normal season and the U.S. East Coast has an elevated risk of seeing landfalling tropical storms and hurricanes this year. The team of researchers from Colorado State University (CSU) unveiled their 2025 seasonal outlook at the 2025 National Tropical Weather Conference in South Padre Island.
CSU’s Tropical Cyclones, Radar, Atmospheric Modeling, and Software (TC-RAMS) Team within the Department of Atmospheric Science cites an above-average subtropical eastern Atlantic Ocean and Caribbean Sea surface temperatures as a primary factor for their prediction of 9 total hurricanes this year, up from the normal 7.2. Overall they expect 17 named storms, up from the usual 14.4.
According to the scientists that worked on the report at CSU, when waters in the eastern subtropical Atlantic are much warmer than normal in the spring, it tends to force a weaker subtropical high and associated weaker winds blowing across the tropical Atlantic. These conditions will likely lead to a continuation of above-average water temperatures across most of the tropical Atlantic for the peak of the 2025 hurricane season. A warm Atlantic favors an above-average season, since a hurricane’s fuel source is warm ocean water. Additionally, a warm Atlantic leads to lower atmospheric pressure and a more unstable atmosphere. Both conditions favor hurricane formation.
In addition to an unusually warm Atlantic, scientists are also looking at conditions over the Pacific which drives conditions not just there, but across the U.S. and the Atlantic hurricane basin too. While the tropical Pacific is currently characterized by weak La Niña conditions, these are likely to transition to El Niño-Southern Oscillation (ENSO) neutral conditions over the next couple of months. There remains considerable uncertainty as to what the phase of ENSO will be during the peak of the Atlantic hurricane season from August to October. However, the odds of El Niño are quite low (13% per the latest NOAA outlook). El Niño – a recurring climate pattern – tends to increase upper-level westerly winds across the Caribbean into the tropical Atlantic. These increased upper-level winds result in increased vertical wind shear, disfavoring Atlantic hurricane formation and intensification. The absence of these conditions, as we anticipate this year, is generally associated with hurricane-conducive upper-level wind conditions across the tropical Atlantic.
“So far, the 2025 hurricane season is exhibiting characteristics similar to 1996, 1999, 2006, 2008, 2011 and 2017,” said Phil Klotzbach, a senior research scientist in the Department of Atmospheric Science at CSU and lead author of the report.
“Our analog seasons ranged from having slightly below-average Atlantic hurricane activity to being hyperactive,” said Klotzbach. “While the average of our analog seasons was above normal, the large spread in observed activity in our analog years highlights the high levels of uncertainty that typically are associated with our early April outlook.”
The 2024 Atlantic Season had a slow start but once it got started in the fall, it became a very busy and destructive season. The 2024 Atlantic hurricane season became the third-costliest on record, behind only 2017 and 2005. The season featured 18 named storms, 11 hurricanes, and 5 major hurricanes; it was also the first since 2019 to feature multiple Category 5 hurricanes. Additionally, the season had the highest accumulated cyclone energy (ACE) rating since 2020, with a value of 161.6 units.
We asked Klotzbach if the 2025 season could have surprises like the 2024 season did. He told us, “For sure, 2024 was quite an unusual season. We had the earliest Category 5 hurricane on record (Beryl), then an extremely quiet ‘climatological peak’ season, followed by one of the busiest season ends on record. While the overall forecast numbers ended up being reasonably close to our seasonal forecasts (except for named storms), it certainly didn’t play out the way that we would have expected.”
Klotzbach added, “I think it’s certainly safe to say that there certainly could be surprises in store for 2025, but we just don’t know what surprises there may be yet.”
This is the 42nd year that the CSU hurricane research team has issued an Atlantic basin seasonal hurricane forecast. The Tropical Meteorology Project team is comprised of several other researchers from the Department of Atmospheric Science including Professor Michael Bell, and Research Scientist Levi Silvers. The department is part of the Walter Scott, Jr. College of Engineering at CSU and is one of the top ranked programs in the world. Professor Emeritus Bill Gray originated the seasonal forecasts in 1984.
The work is supported by sponsorships provided by Weatherboy Weather, the Insurance Information Institute, Ironshore Insurance, Gallagher Re, Insurance Auto Auctions, and Commodity Weather Group. A grant was also used by the G. Unger Vetlesen Foundation.
Weatherboy is also a sponsor of the National Tropical Weather Conference.
While the outlook calls for the number of storms, it doesn’t forecast exactly where they will go. CSU Professor Michael Bell, who helped author the research, warned, “It takes only one storm near you to make this an active season for you.”
And while the forecast doesn’t call for specific landfall locations, it does project which coastlines are more likely to be hit than their climatological norms. In a typical year, there is a 21% chance of an East Coast landfall but in this year’s outlook, those odds are up to 26%. In general, there’s usually a 43% chance of a U.S. landfall; this season, there is a 51% chance.
New Jersey, New York, Connecticut, Rhode Island, South Carolina, and Delaware are all projected to have higher landfall odds than usual in the CSU outlook. New Jersey usually has a 23% chance of a landfall of 1+ storms but this year those odds are up to 28%; Connecticut is usually 22% but this year it is 27%; Rhode Island is usually 20% but is up to 25% this year; South Carolina is usually 57% but up to 66% this year; Delaware is usually 23% but up to 28% this year.
