Triple-I: Updated CSU Atlantic Hurricane Season Forecast Calls for ‘Above-Averag… – Press Release


An updated 2023 Atlantic hurricane season forecast from Colorado State University (CSU) released today projects more tropical cyclone activity than CSU previously anticipated.

Phil Klotzbach, Ph.D., an Insurance Information Institute (Triple-I) non-resident scholar and a senior research scientist in the Department of Atmospheric Science at CSU, and his colleagues are forecasting 18 named storms (including the four that have already formed), nine hurricanes and four major hurricanes. Major hurricanes are defined as those with wind speeds reaching Category 3, 4 or 5 on the Saffir-Simpson Hurricane Wind Scale. In its last forecast issued on June 1, CSU envisioned 15 named storms, seven hurricanes, and three major hurricanes this season.

Three named storms (Arlene, Bret and Cindy) formed in the Atlantic basin in June and an unnamed subtropical storm formed in January. Fourteen named storms, seven hurricanes, and three major hurricanes develop in a typical year, according to the National Oceanic and Atmospheric Administration (NOAA).

“We have increased our forecast and now call for an above-average Atlantic basin hurricane season in 2023, although uncertainty with this outlook is larger than normal,” Klotzbach said. “While we continue to anticipate a robust El Niño for the peak of the Atlantic hurricane season, most of the tropical and subtropical Atlantic now has record warm sea surface temperatures.”

Klotzbach added, “El Niño increases vertical wind shear in the Caribbean and tropical Atlantic, but the extreme anomalous warmth in the tropical and subtropical Atlantic may counteract some of the typical El Niño-driven increase in vertical wind shear.”

The probability of a major hurricane landfall along the coastlines of the continental U.S. this season is estimated to be 50 percent, which is above the long-period average (1880-2020) of 43 percent.

“Those residing in hurricane-prone states should take steps now to reduce their risks from wind and…