An active but relatively harmless hurricane season ends today.
Meteorologists warned the country in the spring to brace for an active season. Barry Keim, Louisiana’s state climatologist, says those warnings proved to be correct, although few storms made landfall in the U.S.
“The season’s certainly lived up to its expectations,” Keim said. “The catch is that the U.S. hasn’t been hurt much by it.”
This year’s 19 named storms ties for the third-most active hurricane season on record.
It’s also significantly more than the 10 named storms spawned in an average season.
“We practically had two hurricane seasons in one this year,” Keim said.
The year tied with 1995 and 1987 and was only less active than 1993’s 21 storms and 2005’s 28 storms.
Despite the season’s number of storms, the U.S. got off relatively lightly. Only two of the season’s seven tropical storms made landfall – Bonnie, which made landfall in South Florida in July, and Hermine, which hit Texas in early September.
None of the season’s 12 hurricanes made landfall in the U.S.
“It was the quietest active season we’ve had in a while,” Keim joked.
Keim says two large-scale weather phenomena contributed to the season’s intensity. First, a phenomenon known as the Atlantic multidecadal oscillation has increased surface temperatures of the ocean waters.
“We’re at the positive [warm] end of the AMO,” Keim said.
Warmer water fuels more and more intense storms.
Second, Keim says a mild or weak “La Nina” created favorable air conditions, which allowed the warm water-fueled cyclones to build up strength.
However, Keim says two high-pressure systems diverted the storms away from the U.S.
The first, “Bermuda High,” is a recurring system that sits off the country’s eastern seaboard, spinning clockwise.
Hurricanes that come through the Atlantic are routed around the edge of the front.
The High’s location routinely changes, pulling hurricanes either closer to or further away from land. This year, the front was further away from shore, routing most of the major storms east, out of harm’s reach.
A second front sitting over the Gulf of Mexico also routed storms that spawned South of the Gulf Coast — a blessing for workers struggling to repair the leaking BP oil well.
Keim said he predicts another active system” next year.
He said the next seasons’ severity hinges on La Nina, which is predicted to last at least until the spring.
“If [La Nina] persists into the summer, we’ll see numbers like this again,” he said.
The year follows a calm 2009, when no hurricanes made landfall.
No major hurricane — a class 3 hurricane or greater — has hit the U.S. since 2006. Keim says that has only happened two or three times since records have been kept.
“If we go one more year, we’ll break the records,” Keim said.
 
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Contact Matthew Albright at [email protected]