It’s official. It’s been 10 years since the last major hurricane landfall in the U.S. when Hurricane Wilma impacted Florida on October 24, 2005.
There has been no shortage of Atlantic hurricane opportunities over the past 10-years to make landfall in America.
All told, there have been 146 named tropical storms — 65 of which became hurricanes — and 27 majors have occurred since Hurricane Wilma made landfall in Florida. Last month’s Hurricane Joaquin was the 27th Atlantic major hurricane in a row to miss the U.S. at major strength.
Recent research may call the 10-year drought “dumb luck,” but there are likely yet unknown climatological reasons tied to the geographical distribution of the last decade’s worth of Atlantic hurricanes.
Words matter in meteorology and climate science words matter, and definitions and metrics are often adjusted, redefined, or reinterpreted. Many of our historical scientific records are fluid — in a constant state of flux — as we increase our understanding of the past via new information or technology.
For example, government scientists erased the “global warming hiatus” from temperature records earlier this year by reprocessing historical temperature records using a new methodology.
Ten years after Hurricane Andrew’s landfall in 1992, the storm’s intensity was upgraded to Category Five over southeast Florida.
From the public’s point of view, it looks like scientists are fiddling with the books, changing data and numbers with a preconceived outcome in mind. In the case of our Atlantic hurricane records, however, considerable uncertainty exists in our estimates of the past due to insufficient or poor observations.
Indeed, significant efforts are underway to “reanalyze” historical storms using current knowledge and techniques. Case in point, a new research paper by Robert Hart of Florida State University highlights uncertainty in the 10-year major hurricane landfall “drought.”
Hart importantly notes that slightly changing the wind threshold definition of a major hurricane can yield dramatically different results.
We do not have to dig far into the weeds to understand this argument.
A major hurricane must have maximum sustained surface winds of at least 96 knots. Historical hurricane records, however, are reported to only 5-knot intervals so 95 knots does not cut it.
You need 100 knots to reach Category Three, or major hurricane status. If a 5-knot buffer or uncertainty interval is plopped on top of the record book, then Hurricane Ike from 2008 qualifies at 95-knots, reducing our landfall “drought” by three years.
Ramp up the major hurricane threshold to 105-knots and 1993-2003 qualifies as a previously unrealized 11-year drought period. Following that logic, the hyperactive hurricane seasons of 2004-2005 actually occurred in between two decade-long droughts.
That would mean the U.S.’s hyperactive hurricane experience appears to be best explained by an extreme “clump” surrounded by two droughts.
Of course since Wilma, other hurricanes named Irene (2011) and Sandy (2012) made landfall along the U.S. East Coast and no one would argue their damage or economic impact was anything less than “major.”
Cuba, on the other hand, has absorbed the brunt of their fair share of major hurricanes.
Both Hurricanes Irene (2011) and Sandy (2012) had the barometric pressure typically seen with a major hurricane (< 960 hectopascals) at landfall but failed to achieve the wind threshold due to their large size. The damage and economic impact from the storms were extreme due to factors like storm surge and coastal flooding.
Major hurricane landfalls will return someday — perhaps in bunches — like we saw in the 1950s and 2004-2005. If there is anything we can learn from our seemingly uncertain climate past, then it should be that history repeats itself, especially with the weather.
Dr. Ryan Maue is a research meteorologist for WeatherBELL Analytics.