A slightly above-average Atlantic hurricane season is likely in 2018, said the hurricane forecasting team from Colorado State University (CSU) in their latest seasonal forecast issued April 5. Led by Dr. Phil Klotzbach, with coauthor Dr. Michael Bell, the CSU team is calling for an Atlantic hurricane season with 14 named storms, 7 hurricanes, 3 intense hurricanes, and an Accumulated Cyclone Energy (ACE) of 130. The long-term averages for the period 1981 - 2010 were 12 named storms, 6.5 hurricanes, 2 intense hurricanes, and an ACE of 92. The CSU outlook also calls for a 63% chance of a major hurricane hitting the U.S. in 2018 (long term average is 52%), with a 39% chance for the East Coast and Florida Peninsula (long term average is 31%), and a 38% chance for the Gulf Coast (long term average is 30%). The Caribbean is forecast to have a 52% chance of seeing at least one major hurricane (long term average is 42%).
Five years with similar pre-season February and March atmospheric and oceanic conditions were selected as “analog” years that the 2018 hurricane season may resemble. These years were characterized by weak La Niña to weak El Niño conditions during August-October, but with a wide variety of tropical and North Atlantic sea surface temperature (SST) patterns, due to the large uncertainty as to what the Atlantic SSTs will look like this summer and fall:
1960 (8 named storms, 4 hurricanes, and 2 intense hurricanes)
1967 (8 named storms, 6 hurricanes, and 1 intense hurricane)
1996 (13 named storms, 9 hurricanes, and 6 intense hurricane)
2006 (10 named storms, 5 hurricanes, and 2 intense hurricanes)
2011 (19 named storms, 7 hurricanes, and 4 intense hurricanes)
The average activity for these years was 11.6 named storms, 6.2 hurricanes, 3.0 major hurricanes, and an ACE of 114—slightly above the long-term average. The most notable storms during these years were Category 4 Hurricane Donna of 1960, Category 5 Hurricane Beulah of 1967, Category 3 Hurricane Fran of 1996, and Category 3 Hurricane Irene of 2011.