With Erin on verge of being a hurricane, tropical experts update storm season forecast
The tropical weather experts at Colorado State University aren’t backing off their predictions of another active Atlantic hurricane season.
Even if there’s only been four tropical storms, including last week’s Dexter that roamed harmlessly across the northcentral Atlantic, the flipping of the calendar to August should spark an uptick in activity, as history and climatology have dictated over the years and decades.
On the heels of the first bona-fide storm forming in the Atlantic potentially becoming Hurricane Erin this week, the CSU researchers are maintaining their forecast for 16 named storms, eight hurricanes and three major (Category 3-5) ones.
That means the team forecasts eight storms with maximum sustained winds of 74 mph or more to form over the three-and-a-half months. That isn’t out of the ordinary —the climatological peak of hurricane season occurs on Sept. 10 and formation chances stay high into October.
The Weather Channel notes, on average, the first hurricane of the year is spawned on Aug. 11, and with a conveyor belt of tropical waves about to exit western Africa and enter the ocean, that may come over the next week or so.
CSU’s Tropical Cyclones, Radar, Atmospheric Modeling, and Software (TC-RAMS) team within the Department of Atmospheric Science said it cites above-average tropical Atlantic Ocean and Caribbean Sea surface temperatures as a primary factor for their prediction of eight total hurricanes this year.
“The tropical Atlantic has warmed faster than normal over the past few weeks, due to relatively weak winds blowing across the area, leading to less evaporation and mixing of the ocean surface,” the CSU team’s report said. “Warmer than normal waters in the tropical Atlantic and Caribbean Sea tend to favor 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.
The experts also noted a lack of El Niño conditions—a recurring climate pattern that tends to increase upper-level westerly winds across the Caribbean into the tropical Atlantic.
The team predicts that 2025 hurricane activity will be about 115% of the average season from 1991–2020. By comparison, 2024’s hurricane activity was about 130% of the average season—and that was the season that brought hurricanes Debby, Helene and Milton to the Gulf Coast of Florida.
For more of the August CSU report, go to: tropical.colostate.edu/forecasting.html.
