MIAMI – Sept. 9, 2013 – The preseason predictions were all dire, using words like “extremely active” and “above-normal” to describe the forecast for the 2013 Atlantic hurricane season. The National Oceanic and Atmospheric Administration (NOAA) predicted that seven to 11 hurricanes would form, while AccuWeather predicted eight.
The season so far has been a welcome if unexpected dud, with not a single hurricane yet through the first week of September. (A typical full June-November hurricane season, based on weather records that go back to 1950, has seven hurricanes.)
In fact, the season is about to enter record territory for its unusual lack of hurricanes.
“If the first hurricane of 2013 forms after 8 a.m. on Sept. 11, it would set a record for the latest ‘first’ hurricane to arrive in the satellite era (1967 and later),” said Dennis Feltgen, spokesman with the National Hurricane Center in Miami. He said the current record holder is 2002’s Gustav, which formed on Sept. 11 of that year.
So, what’s happened to all of the expected hurricanes this year?
Several tropical storms – of which there have been seven so far – dissipated when they ran into dry air and wind shear, Feltgen said, and did not affect the USA. Wind shear – strong winds that roar from different directions at various levels of the atmosphere – can tear apart developing hurricanes.
Strong winds blowing west off of the Sahara Desert have helped bring dry, dusty air into the Atlantic Ocean this summer, which can tend to decrease hurricane formation, AccuWeather said.
A tropical storm becomes a hurricane when its sustained winds reach 74 mph or greater.
“Several tropical waves coming across the tropical Atlantic in recent weeks have run into the same environmental issues and have failed to develop any further,” Feltgen said. Tropical waves are small weather disturbances that spin off Africa’s western coast, which sometimes can strengthen into tropical storms and eventually hurricanes.
“Even though dry air has backed off a little in recent days, strong westerly winds aloft continue to interrupt tropical development for almost every budding system,” according to AccuWeather hurricane expert Dan Kottlowski.
Experts warned against complacency.
“We are only at the midpoint of the six-month hurricane season, and have just entered the peak of the hurricane season (mid-August through late October),” Feltgen said. “It is a mistake to believe that the second half of the season would resemble the first half.”
As of Sunday afternoon, the hurricane center was monitoring two tropical disturbances in the Atlantic, one of which may develop into the season’s first hurricane by week’s end. However, even if it does form, it’s not forecast to affect the USA.
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