Monday, May 4, 2015

No Major Hurricane Has Made Landfall In the U.S. In More Than 9 Years -- and That's a New Record

Linda Lam
Published: May 1,2015




 
The U.S. is in new record territory, as the nation passes the nine and a half year mark without the landfall of a major hurricane. But what researchers believe is behind the so-called hurricane drought might surprise you.
A hurricane is considered a "major hurricane" when it reaches at least Category 3 status, with maximum sustained winds of 111 mph or greater on the Saffir-Simpson Hurricane Wind Scale. Hurricane Wilma was the last major hurricane to make landfall in the U.S., when it came ashore on October 24, 2005 near Cape Romano in southwestern Florida as a Category 3 storm; Wilma actually peaked as a Category 5 as it spun in the Caribbean Sea.
(MORE: Florida Lack of Landfalls Streak)
This is now the longest streak since hurricane records began in 1851. The previous record was a little over nine years, set from August 11, 1860 to September 8, 1869.
According to NOAA, on average, about two major hurricanes every three years make landfall somewhere along the Gulf or Atlantic coast. The year with the most is 2005, when four major hurricanes made landfalls in the United States (Dennis, Katrina, Rita and Wilma).
Timothy Hall of the NASA Goddard Institute for Space Studies is the lead author of a new study, published in the American Geophysical Union, examining how unusual this stretch really is. Hall and Kelly Hereid used a computer model, which took into account major facts that enable or suppress hurricanes, to simulate the years 1950-2012 under a variety of conditions.
The results of the study indicate that the mean time to wait for a nine-year major hurricane drought is 177 years.
So what's causing this streak? Hall says he and his team didn't find much had changed. Instead, he's chalking it up to luck.
Colorado State Universtiy meteorologist Phil Klotzbach, who was not a part of the study, agrees. "I think that there has been a significant 'luck' component involved. But there has also been a predominant trough along the East Coast from 2006-2014, which has generated steering currents that have tended to push the storms away from the U.S. coast."
Hurricane Wilma in 2005 (NOAA).
One of the reasons researchers believe that there hasn't been a real change in hurricane seasons is that Atlantic hurricane seasons have been average, as measured by accumulated cyclone energy (ACE) since 2006. ACE is a measure of tropical cyclone activity, taking into account the number, strength and duration of all the tropical cyclones in a season. According to the researchers, "The 2006-2014 annual mean ACE is 97, compared to a 1951-2000 mean of 93."
In addition, major hurricanes have developed in the past nine years, they just have not made landfall in the United States. Last year, two major hurricanes developed, Edouard and Gonzalo; but Edouard stayed far out in the Atlantic, while Gonzalo impacted Bermuda and the eastern Caribbean. And while Hurricanes Ike and Gustave in 2008 were destructive to U.S. soil, they fell just short of that major hurricane status, as the Washington Post points out.
(MORE: 2014 Hurricane Season)
A total of nine named storms -- five hurricanes and one major hurricane -- are expected this season, according to the forecast prepared by The Weather Channel Professional Division. This is below the 30-year average of 12 named storms -- six hurricanes and three major hurricanes.
(MORE: 2015 Atlantic Hurricane Forecast)
However, it is important to remember that it just takes one hurricane to bring devastation.
MORE: Hurricane Wilma Photos

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