Weak year due to El Nino ahead but the analog years they picked were active in the GOMEX with Betsy and Audrey being biggies.
A slightly below-average Atlantic hurricane season is likely in 2017, said the hurricane forecasting team from Colorado State University (CSU) in their latest seasonal forecast issued April 6. Led by Dr. Phil Klotzbach, with new coauthor Dr. Michael Bell, the CSU team is calling for an Atlantic hurricane season with 11 named storms, 4 hurricanes, 2 intense hurricanes, and an Accumulated Cyclone Energy (ACE) of 75. 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 42% chance of a major hurricane hitting the U.S. in 2017, with a 24% chance for the East Coast and Florida Peninsula and a 24% chance for the Gulf Coast. The Caribbean is forecast to have a 34% chance of seeing at least one major hurricane. All of these probabilities are slightly below the long-term numbers from the last century.
Five years with similar pre-season February and March atmospheric and oceanic conditions were selected as “analog” years that the 2017 hurricane season may resemble. These years were characterized by neutral to weak La Niña conditions the previous year, with a transition to weak or moderate El Niño conditions during the current year:
1957 (8 named storms, 3 hurricanes, and 2 intense hurricanes)
1965 (6 named storms, 4 hurricanes, and 1 intense hurricane)
1972 (7 named storms, 3 hurricanes, and 0 intense hurricane)
1976 (10 named storms, 6 hurricanes, and 2 intense hurricanes)
2002 (12 named storms, 4 hurricanes, and 2 intense hurricanes)
These five years all featured neutral conditions in the Eastern Pacific transitioning to El Niño conditions. The average activity for these years was 8.6 named storms, 4 hurricanes, and 1.4 major hurricanes--below the long-term average. The most notable storms during these years were Hurricane Audrey of 1957, Hurricane Betsy of 1965, and Hurricane Agnes of 1972.