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But don't get too cocky, forecasters say.
Although the first named storm in the Atlantic typically forms by July 10, the real activity doesn't usually begin until August. And a lull in early-season activity does not necessarily indicate a weak overall season.
The 2004 season, for example, didn't see its first storm until Hurricane Alex began developing July 31.
Yet after Alex, the season rapidly took off, finishing with 15 storms and 6 major hurricanes, including Hurricane Ivan. A storm the size of Texas, Ivan was one of the 10 most intense hurricanes ever in the Atlantic basin before striking Gulf Shores, Ala., and causing $19 billion in damage.
And while El Niños may suppress overall activity, such years can still produce savage storms. Hurricane Andrew, one of the three most intense storms at a U.S. landfall, developed during an El Niño in 1992.
So have some of the most famed storms to strike Texas and Louisiana: Alicia (1983), Betsy (1965) and the great storm of 1900, which came during a severe El Niño, said Jill Hasling, president of Houston's Weather Research Center.
“There might be fewer storms during an El Niño,” she said. “But it only takes one.”
During an average Atlantic season, 10 tropical storms or hurricanes develop, but since 1995 the Atlantic has seen an increase in activity that most scientists attribute to a long-term natural pattern.
Given this season's slow start and the onset of El Niño, most seasonal forecasters now say about 10 named storms will form, one of the lowest totals of the past 15 years.
The official start of hurricane season is June 1, but recent years have seen storms form in May.
This happens when frontal boundaries drift south into the Gulf of Mexico or off the East Coast, producing lingering areas of thunderstorms that sometimes spin into tropical storms, said Chris Hebert, lead hurricane meteorologist at ImpactWeather, a private Houston-based forecasting company.
That almost happened this year.
“We did have a few such features in May and June,” he said. “One made it to tropical depression strength, but none made it to tropical storm strength. So it was pretty close in May and June.”
But as often happens in July — and certainly what has happened this year, with especially hot temperatures — high pressure builds across the gulf and the southeastern states, reducing the chances of hurricane development near the U.S.
July storms often form in the Caribbean, but wind shear and other factors there have combined to create hostile conditions for storms, Hebert said.
Looking later into the season, Hebert says a semi-permanent feature called the Bermuda High, a large area of high pressure just north of the tropics, may be quite strong this year. This would limit development in the deep tropics.
Perhaps as hurricane season progresses, storms will be most likely to develop closer to land in the Caribbean or the gulf, he said.
Hebert and other forecasters say such a possibility should concern emergency management experts because these storms give little warning.
Though Hurricane Alicia was bad, spinning up from a tropical depression Aug. 15, 1983, into a Category 3 hurricane two days later before striking Galveston, there are worse precedents during an El Niño year.
Specifically, there's the largely forgotten Texas hurricane of 1932. That storm formed Aug. 11 in the gulf near the Yucatán Peninsula.
A day and a half later, a Category 4 hurricane, with 145-mph winds, slammed into Freeport
Forecasts of hurricane activity are issued before each hurricane season by noted hurricane experts Philip J. Klotzbach, William M. Gray, and their associates at Colorado State University; and separately by NOAA forecasters.
Klotzbach's team (formerly led by Gray) defined the average number of storms per season (1950 to 2000) as 9.6 tropical storms, 5.9 hurricanes, 2.3 major hurricanes (storms reaching at least Category 3 strength in the Saffir-Simpson Hurricane Scale) and ACE Index 96.1.[1] NOAA defines a season as above-normal, near-normal or below-normal by a combination of the number of named storms, the number reaching hurricane strength, the number reaching major hurricane strength and ACE Index.[2]
[edit] Pre-season forecasts
On December 10, 2008, Klotzbach's team issued its first extended-range forecast for the 2009 season, predicting above-average activity (14 named storms, 7 hurricanes, 3 of Category 3 or higher and ACE Index of 125). On April 7, 2009, Klotzbach's team issued an updated forecast for the 2009 season, predicting near-average activity (12 named storms, 6 hurricanes, 2 of Category 3 or higher and ACE Index of 100), citing the possible cause as the high probability of a weak El Niño forming during the season.[3] On May 21, 2009, NOAA issued their forecast for the season, predicting near or slightly above average activity, (9 to 14 named storms, 4 to 7 hurricanes, and 1 to 3 of Category 3 or higher).[4]
[edit] Midseason outlooks
On June 2, 2009, Klotzbach's team issued another updated forecast for the 2009 season, predicting slightly below average activity (11 named storms, 5 hurricanes, 2 of Category 3 or higher and ACE Index of 85). On June 18, 2009, the UK Met Office (UKMO) issued a forecast of 6 tropical storms in the July to November period with a 70% chance that the number would be in the range 3 to 9. They also predicted an ACE Index of 60 with a 70% chance that the index would be in the range 40 to 80.[5]
Predictions of tropical activity in the 2009 season Source Date Named
storms Hurricanes Major
hurricanes
Average (1950–2000) 9.6 5.9 2.3
Record high activity 28 15 8
Record low activity 4 2 0
–––––––––––––––––––––––––––––––––––––––––––––––––– –––––
CSU December 10, 2008 14 7 3
CSU April 7, 2009 12 6 2
NOAA May 21, 2009 9–14 4–7 1–3
CSU June 2, 2009 11 5 2
UKMO June 18, 2009 6* N/A N/A
––––––––––––––––––––––––––––––––––––––––––
* July-November only.