End to 2009 Hurricane Season
With nine named storms, the 2009 season that ends today was the calmest in a dozen years. You have to go back to 1997, which had seven named storms, to find a year with fewer.
For the fourth year, no hurricanes crossed the Florida coastline. The last hurricane to hit Florida was Wilma in 2005.
In fact, the six-month season that officially begins June 1 was really only four months long. The first storm didn't form until Aug. 15.
By all measures, the season was below average and far tamer than some of the hyperactive seasons in the past five years, when an average of 16 named storms formed each season.
"Any way you slice it, it was a quiet year," said Chris Landsea, a science officer at the National Hurricane Center in Miami.
This year's nine named storms were two fewer than what form in an average season. Four of those storms swirled aimlessly in the open ocean. One, Tropical Storm Grace, posed more of a threat to Ireland than the United States.
The activity in 2009 represented 60 percent of a normal season, based on a measure that includes the number of storms, their strength and how long they last.
The three hurricanes this season are half the number seen in an average year. Of those, Hurricane Bill hit Newfoundland, and Hurricane Ida hit Central America.
In the past 20 years, just three seasons saw three hurricanes.
"To only have three hurricanes is rare," Landsea said.
Only two tropical storms, Claudette and Ida, reached this country, and the remains of Ida caused more destruction moving up the Eastern Seaboard than the storm did when it first hit land.
But those two tropical storms did affect Florida. Claudette hit the Panhandle, and Ida's effects stretched east from where it made landfall, in eastern Alabama, to reach Florida.
Storm surge from both caused some coastal flooding and rivers rose, said Amy Godsey, deputy state meteorologist.
"A lot of the impacts were pretty minor because they hit and got out of the area pretty quickly," she said.
This year looked like a flashback to the 1997 hurricane season, the last time a potent El Niño dominated global weather.
During an El Niño, warm water over a vast stretch of the tropical Pacific Ocean creates conditions in the atmosphere hostile to hurricanes. Winds blowing from the west disrupt storms that try to form in the Atlantic, where most storms are born during the August and September peak of the season. The storms that do form get blown apart quickly - a fate many encountered this year.
"With the exception of Hurricane Bill, all weakened not long after they formed," Landsea said.
The El Niño threw early forecasts of how active the season would be out the window.
Before the season started, William Gray and Phil Klotzbach from Colorado State University called for 11 named storms, with five hurricanes and two of those becoming major storms, reaching Category 3 or higher.
The National Oceanic and Atmospheric Administration called for nine to 14 named storms, four to seven hurricanes and one to three becoming at least a Category 3.
The final numbers were nine named storms, three hurricanes and two storms that became at least a Category 3.
When the preseason predictions were made, scientists were unsure how strong an El Niño would be, or even if one would form, Landsea said.
"Some models projected an El Niño but couldn't tell if it would be weak or moderate," he said.
It turns out this El Niño reached moderate strength, and that makes a difference.
A weak El Niño doesn't have the storm-dampening effect on a season that a stronger El Niño produces.
In 2004, when there was a weak El Niño, 15 named storms developed, and four hurricanes hit Florida, Landsea said.
The El Niño factor was the reason this season was so quiet.
"Without the El Niño, it would have been quite a bit more active," Landsea said