The official Sept. 10 peak of the hurricane season has come and gone. Stubborn Nadine, bouncing between tropical storm and hurricane intensity in the far-off Atlantic Ocean over the last two weeks, has posed no threat to anybody. For the moment, nothing else is brewing.
“There’s not a thing out there right now,” said Dennis Feltgen, spokesman for the National Hurricane Center. “The models aren’t showing anything developing in the short term.”
The tropics may be sleeping, but if history is any measure, the season is far from over.
It’s the month of October, in fact, that forecasters say has posed the biggest problem for South Florida.
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“I think there is a perception that once Sept. 10 comes and goes, then, whew, we can breathe a sigh of relief,” said Robert Molleda, a meteorologist for the National Weather Service’s Miami office. “We’re not saying we’re going to get hit. We might not, but it’s too early to let down your guard.”
Since 1851, hurricane center records show 19 storms have struck South Florida in October, compared to 15 in September and 11 in August.
In October, the patterns that produce hurricanes tend to shift. Tropical waves rolling off Africa and spinning up off the Cape Verde Islands begin to dissolve as ocean waters start to cool and winds aloft begin to strengthen.
At the same time, stirrings in the Caribbean Sea and the Gulf of Mexico tend to pick up as cold fronts pushing down from the north collide with the warm, moist atmosphere to the south, often sparking storms. A bi-weekly forecast produced by Colorado State University climate scientists Phil Klotzbach and William Gray predicts an average level of activity over the next few weeks, with potential rising toward the middle of the month.
For Florida, location is the primary problem with October storms — they form to the south and tend to move north, with less time and space to veer harmlessly out to sea.
“If you form in the western Caribbean or the Gulf of Mexico, you’re probably going to hit land somewhere,” hurricane center Director Rick Knabb said. “We’ve seen a lot of storms in the past affect South Florida from the south. Think of Wilma in 2005 and Irene in 1999.”
Later season storms also can prove powerful. At one point while in the Caribbean, Hurricane Wilma’s winds reached 185 mph and became the most intense Category 5 hurricane ever recorded in the Atlantic basin. The storm would eventually do some $29 billion in damage in Florida, Cuba and the Yucatán Peninsula and kill more than 60 people.
Though tropical storms can form at any time of year, the official season tends to slow in November before ending on Dec. 1.