CSU Adjusts Atlantic Hurricane Season Forecast Due to Emerging El Niño

The growing likelihood of an El Niño to emerge this summer has led Colorado State University hurricane researchers to slightly reduce their original forecast for the Atlantic hurricane season.

In the latest forecast published June 10, CSU predicts a below average hurricane season of 11 named storms, of which five are anticipated to be hurricanes and two as major hurricanes. The original forecast in April called for 13 named storms, six hurricanes and two major hurricanes.

An average hurricane season has 14 named storms, seven hurricanes, and three major hurricanes.

The CSU team anticipates a moderate to strong El Niño to form by the peak hurricane season of August-October. El Niño is a recurring climate pattern that occurs every two to seven years, characterized by warmer than normal water in the central and eastern tropical Pacific.

Related: Weathering NOAA’s ‘Below Normal Atlantic Hurricane Season’ And A Super El Niño

“When you get an El Niño, it tends to increase winds high up in the atmosphere in the Atlantic, which basically cause a lot of sheer—strong winds that tear apart hurricanes as they’re trying to develop and intensify,” said Phil Klotzbach, a senior research scientist in the Department of Atmospheric Science at CSU. “In general, when you get moderate to strong El Niños, like we think we’re going to get this summer and fall, it really tends to knock down Atlantic hurricane activity pretty substantially.”

Water temperatures in the central and eastern tropical Atlantic are cooler than normal, which favors below-normal hurricane activity.

The CSU team predicts 2026 hurricane activity will be about 60% of the average season from 1991–2020 and a departure from the past decade. Nine of the past 10 years have been above normal or hyperactive, with 2022 as the lone exception.

Related: US Forecaster Says El Niño Has 82% Chance of Developing by July

While this hurricane season is forecast to be below average, there will probably be little pockets in certain areas where conditions are conducive for a storm, Klotzbach said. The overall conditions of El Niño, however, don’t tend to give major hurricanes much room to develop.

“Typically we see pretty strong knockdowns of major hurricanes, because you can get a weak storm in a pretty marginal environment, whereas to get a very strong storm you need a pretty large area of conducive conditions,” Klotzbach said.

The latest forecast from CSU gives a 24% chance of a major hurricane making landfall along the U.S. coastline (the average from 1880–2020 is 43%).

Atlantic hurricane season runs from the beginning of June through the end of November, with about 95% of major hurricane activity occurring after August 1.