Over the last five Atlantic hurricane seasons (from 2006-2010), tropical storms and hurricanes have had little trouble brewing. In fact, 69 named storms spun up in the Atlantic and Gulf of Mexico, about 35 percent above the long-term average. 34 of those storms grew into hurricanes and 16 major hurricanes (category 3 or higher on the Saffir-Simpson scale). Yet, of all those major hurricanes, not one made landfall along the coast of the United States.
The last major hurricane to strike the U.S. coast was Wilma in October, 2005, coming ashore in southwest Florida. According to Dr. Adam Lea, a tropical cyclone research fellow at University College of London, the period spanning 2006 to 2010 is one of only three 5-year periods on record (the other two: 1901-1905 and 1936-1940) without a major hurricane making landfall in the United States. “If there’s not one at all this year [in 2011], it will be the longest period between landfalls [on record],” he said.
And it’s not just the big ones playing keep away from the U.S. coast. The last storm to make a direct hit on the U.S. was Ike in September 2008. It’s now been more than 1,000 days since any hurricane (irrespective of intensity) has struck the U.S. mainland. That’s an unusually long stretch without a landfall, but not unprecedented according to Dr. Phil Klotzbach, hurricane researcher at Colorado State University.
“We’ve had these kinds of periods before,” he said. “There was a patch in the early 80s [between Allen and Alicia] and a stretch from October 15, 1999 [Irene] to October 13, 2002 [Lili]”.
Historically, about one in four hurricanes that forms in the Atlantic makes landfall in the U.S.. In 2010, for all 12 hurricanes that developed to avoid the U.S. represented just a 3% chance according to Klotzbach.
“We were really lucky,” he said.
Going back to 2008 when Hurricane Ike ravaged the southeast coast of Texas, 18 straight hurricanes have missed the U.S. coast. (During the quiet stretch from 1999-2002, there were 22 consecutive hurricanes between landfalls).
Lea does not expect this lull in activity to continue for long.
“I don’t think this drought in U.S. landfalls can go on forever,” he said. “I would expect at least one or two hurricanes [to make landfall in the U.S.] this year.”
The consensus among Atlantic hurricane outlooks in 2011 is for another busier than normal season. And there are subtle signs the Atlantic hurricane season is beginning to bubble up.
This afternoon, an Air Force hurricane hunter will investigate a disturbed area of weather in the Gulf of Mexico’s Bay of Campeche that has a 70 percent chance of becoming a named storm. Yet even if this disturbance earns a name, there’s effectively no chance it will strengthen into a hurricane or major hurricane and strike the U.S. coast.