Respite from hurricanes over, forecasters say
Multiple factors point to a year more like 2004 or '05 for Florida.
By STEPHEN NOHLGREN
Published April 4, 2007
Ocean temperatures, dust in Africa and the shape of high-pressure systems all indicate that Florida could soon expect another round of submerged neighborhoods, blue tarp roofs and FEMA trailers.
That's the grim outlook predicted Tuesday by three separate research groups that updated their 2007 hurricane forecasts.
Global climate signals "raise images of 2004 and 2005," said Ken Reeves, forecasting director for AccuWeather.com, referring to hurricanes that clobbered Florida and other gulf states two years running.
"That's the kind of hurricane season we have to worry about."
William Gray, longtime hurricane researcher at Colorado State University, predicted that 17 storms would intensify enough to be named by the National Hurricane Center. Of those, nine would reach hurricane strength, including five major hurricanes, Gray's group said.
Gray predicted a 74 percent chance that a major hurricane would hit the United States, up from an average of 52 percent.
Tropical Storm Risk Inc., a British company that serves the insurance industry, also predicted 17 named storms and nine hurricanes.
Last year's modest hurricane season was probably just a respite in otherwise stormy times, they agree.
Such forecasts, though, often miss their mark, particularly when they are made in April, two months before the hurricane season begins.
In 2005, the Atlantic basin spawned a record 28 named storms, almost doubling most expectations.
Last year, many forecasters predicted another busy season, but not a single hurricane made landfall in the United States.
Atmospheric and oceanic modeling remains in its infancy.
Still, Tuesday's round of predictions brought broad agreement among groups that sometimes see different patterns in the tea leaves.
The National Hurricane Center won't make its first official prediction until May 22, but generally agrees that 2007 should be busier than most years, said meteorologist Dennis Feltgen.
"We remain in a very active hurricane cycle" that began in 1995, Feltgen said. "We assume we will be in this for the next 10 to 15 years."
One key indicator is water temperature in the tropical Pacific. When it's warm, it can cause El Nino conditions, which alter weather throughout the Americas and tend to hinder Atlantic hurricanes.
Last year, both Gray's group and the hurricane center were caught by surprise by a strong, late-developing El Nino. That's why their predictions of a busy season never materialized, they said.
That warm Pacific water dissipated in December. Now, temperatures in the Pacific are slightly cooler than normal, pointing to a possible La Nina, which stimulates Atlantic hurricanes, said Phillip Koltzbach, one of Gray's associates.
About 20 computer models track those Pacific effects, Koltzbach said, "and about half are predicting La Nina and about half are neutral. Only one is predicting El Nino."
Unlike other forecasters, AccuWeather.com correctly predicted a quiet hurricane season last year for Florida and other states along the Gulf of Mexico. AccuWeather.com focuses on landfalls and hurricane tracking more than on total numbers of storms, said Reeves, the forecasting director.
Multiple factors point to a busy year for Florida and the gulf, he said.
Atlantic and gulf water temperatures are high, which feed big storms. Dust from Africa, which can sap energy from potential storms, is more likely to stay in Africa this year. And an Atlantic high-pressure ridge seems to be forming in an elongated shape that pushes storms more toward Florida and the gulf rather than up the Eastern Seaboard or out into the Atlantic, Reeves said.
"All the analogs really point to, after a breather last year, it's back to above-normal conditions in the gulf," he said.
Starting to make your hurricane supply list? New to the state and need to know what to buy? Visit weather.tampabay.com/hurricane/.
- Colorado State University forecast: hurricane.atmos.colostate.edu/.
- National Hurricane Center: www.nhc.noaa.gov/.
- National Weather Service: www.nws.noaa.gov/.
[Last modified April 3, 2007, 23:11:29]
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