The 11-Year Major Hurricane Drought: Much More Unusual than Two Cat 4 Strikes

Roy W. Spencer, Ph. D.
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The Probability of the 11-Year “Drought” in Major Landfalling Hurricane
In 2015, a NASA study was published which calculated how unlikely the (then) 9-year stretch with no major hurricane landfalls was. They came up with a 177 year return period for such an event.
I used that statistic to estimate what eventually happened, which was 11 years with no major hurricane strikes.
I get a return period of 560 years!
Now, which seems more unusual and potentially due to climate change: something that should happen only once every 50 years, or every 560 years?
Maybe global warming causes fewer landfalling major hurricanes."