Climatologist Dr. Roy Spencer: Those who are old enough to remember might recall that after the devastating 2005 season (remember Katrina?), this was going to be the “new normal” for Atlantic hurricane activity due to global warming. There were 15 hurricanes that year. The next year (2006) the bottom dropped out. The National Hurricane Center expected system after system to strengthen, and it almost never happened.
Has there been any long term trend in Atlantic tropical cyclone activity? If so, it has been slightly downward. Here is Ryan Maue’s tropical Accumulated Cyclone Energy (ACE) index for the Atlantic, which monitors the total 3-D wind energy contained in tropical cyclones. It shows that the current lull in activity matches the lull back in the late 1970s and early 1980s:
