BOSTON – The 2013 Atlantic hurricane season is humbling forecasters by shaping up as the first in almost two decades without a major storm, confounding predictions that it would be more active than normal.
It’s been two weeks since the season’s statistical peak and just days are left in its busiest month. With the Atlantic full of dry air and storm-killing winds, there isn’t anything in sight that poses a threat to the United States or to oil and gas production areas in the Gulf of Mexico.
Except for Tropical Storm Andrea, which formed in the Gulf of Mexico in June and crossed Florida to New England, contributing to the deaths of four people, the United States has been spared a hit. Last year, four tropical systems struck, including hurricanes Isaac and Sandy, which together caused more than $52 billion in damage and killed at least 179 people.
“The season looks to be a huge bust,” said Phil Klotzbach, lead author of Colorado State University’s annual storm forecast. “That’s one of the fun things about being in the weather business. It definitely keeps you humble.”
Colorado State, which pioneered seasonal hurricane outlooks, in August predicted an above-average 18 storms, eight of them hurricanes and three of them major systems. The National Oceanic & Atmospheric Administration said there was a 70 percent chance for 13 to 19 storms, six to nine of them hurricanes and three to five of them major.
The predictions were based on warmer sea temperatures, a strong West African monsoon and the lack of a Pacific El Niño, a phenomenon that can create Atlantic wind shear.
The shear, winds that blow at different speeds or directions at varying altitudes, ripping storms apart, “has been relentless out there” despite the absence of an El Niño, said Matt Rogers, president of Commodity Weather Group in Bethesda, Md.
Mid-level relative humidity across the tropical Atlantic, typically about 30 percent, has been down to 20 to 25 percent this year, Klotzbach said.
“It’s been dry out there, and when I say dry, I mean dry,” Klotzbach said. ‘I’m still not quite sure why it’s been as dry as it has.’’
Warmer waters and the African monsoon haven’t been enough to counter the shear and dryness.
If no major hurricane, one with winds of 111 mph or more, forms in the Atlantic this year, “it will be the first time since 1994,” Rogers said.
There were still storms, however. Mexico was battered this month on both coasts by storms that killed at least 130 people and left dozens missing.
The calmer weather has offered a reprieve for U.S. property insurers. The companies are also benefiting from rate increases they pushed through as claims costs rose and low interest rates reduced income from bond portfolios that back up policyholder liabilities.