August is about to end without an Atlantic hurricane for the first time since 2002, calling into question predictions of a more active storm season than normal.
Six tropical systems have formed in the Atlantic since the season began June 1 and none of them has grown to hurricane strength with winds of at least 74 miles (120 kilometers) per hour. Accumulated cyclone energy in the Atlantic, a measure of tropical power, is about 30 percent of where it normally would be, said Phil Klotzbach, lead author of Colorado State University’s seasonal hurricane forecasts.
“At this point, I doubt that a super-active hurricane season will happen,” Klotzbach said in an e-mail yesterday.
The most active part of the Atlantic season runs from Aug. 20 to about the first week of October. The statistical peak occurs on Sept. 10, according to the National Hurricane Center in Miami. Two storms formed in August and the hurricane center is tracking two areas of thunderstorms that have low to medium chances of becoming tropical systems within five days
Atlantic storms are watched closely because they disrupt energy operations in and around the Gulf of Mexico and cause widespread destruction when they come ashore.
In the basin now, warm sea water and a decreasing amount of wind shear that can tear at the structure of budding storms mean conditions are ripe “for a burst of activity,” said Todd Crawford, chief meteorologist at Weather Services International in Andover, Massachusetts.
“The very inactive season so far has been a bit of a head-scratcher,” Crawford said in an e-mail interview.
Air temperatures from the Caribbean to Africa have been warmer than normal this year, reducing the instability in the atmosphere that drives storm development, he said. In addition, dry air is being pulled off Africa into the Atlantic, which also cuts storm activity, he said.
Seasonal predictions were for an above-normal season. The 30-year average is for 12 storms with winds of at least 39 miles per hour, the threshold at which they are named. Nineteen such systems formed in each of the last three years.
Colorado State, which pioneered seasonal forecasts, retreated slightly on its outlook in an early August update, calling for 18 named storms. Eight should be hurricanes and three of them major hurricanes, a reduction of one at each level, the researchers said.
The National Oceanic & Atmospheric Administration also kept its call for an above-average season in an Aug. 8 outlook for 13 to 19 named storms, six to nine hurricanes and three to five major systems.
“If you don’t get your first hurricane by or before August, it’s extremely difficult to get those high storm counts, especially for hurricanes and major hurricanes,” said Matt Rogers, president of Commodity Weather Group LLC in Bethesda, Maryland. “Amazing we’re on the 90th day of the hurricane season and no hurricanes yet.”
While water temperatures in the Atlantic, Caribbean and Gulf of Mexico are high enough to spark hurricane formation, wind shear across the central part of the ocean has been high, Klotzbach said.
Shear is when the winds at different altitudes blow at varying speeds or directions, which can tear at the structure of a budding tropical system.
According to the U.S. Climate Prediction Center, there has been a lot of wind shear in the Atlantic between the Lesser Antilles in the Caribbean and Cape Verde off the coast of Africa. This zone is often referred to as the main development region for Atlantic hurricanes, particularly in August and September.
“We haven’t had a hurricane and we don’t see anything that looks highly robust,” said Dan Kottlowski, an expert senior meteorologist at AccuWeather Inc. in State College, Pennsylvania. “It just goes to show you that having warm water isn’t everything.”
For natural gas markets, hurricanes have shifted from being major output disruptions, in part because so much production has shifted to land, to being “load killers” that cut electricity demand as temperatures drop, said Teri Viswanath, director of commodities strategy at BNP Paribas SA in New York.
The Gulf of Mexico is home to about 6 percent of U.S. natural gas output, 23 percent of oil production and more than 45 percent of petroleum refining capacity, according to the U.S. Energy Department. In 2001, Gulf waters accounted for 24 percent of U.S. marketed gas production.
A quiet first half to the Atlantic storm season doesn’t mean the second will be the same, she said.
“It’s not over until it’s over,” Viswanath said.
Hurricane Sandy, which slammed into New York and New Jersey last year, developed on Oct. 22 and went ashore on Oct. 29. It killed at least 159 people and damaged or destroyed more than 650,000 homes in the U.S., according to a federal task force report Aug. 19.
Crawford also said the 2013 season could rebound now that September has begun. He expects some of the barriers that have damped activity so far to fall.
The 2002 season, the last to pass without a hurricane by the end of August, included Hurricane Lili, a Category 4 storm that caused about $860 million in damage and killed at least 13 people in the Caribbean and Louisiana from Sept. 21 to Oct. 4, according to the hurricane center. The first hurricane to form that year was Gustav, on Sept. 11.
“On Sept. 9, if there is nothing to talk about, you can call me and we can write off the season,” said Michael Schlacter, founder of Weather 2000 in New York. “I think in the next 10 days there will be a lot of things to discuss.”