Forecasters: September Will Be Busy Month for Hurricanes

Tornado Science, Facts and History

As the remains of Gustav soak the Southern states and Hanna threatens the U.S. East Coast, hurricane forecasters are predicting that September will be a very busy month for Atlantic storms. A forecasting team at Colorado State University said today that the Atlantic basin is expected to experience five named storms this month. Yesterday marked the first time since the hellacious 2005 hurricane season — the busiest on record — that three named tropical cyclones churned in the Atlantic basin at the same time. Besides Gustav and Hanna, Tropical Storm Ike formed on Sept. 1, followed by Tropical Storm Josephine on Sept. 2. The Colorado State team has predicted that four of the five named storms will become hurricanes, with two becoming major hurricanes (Categories 3, 4 and 5 on the Saffir-Simpson scale, which is based on a storm's top sustained wind speed). This would be well above-average activity for September, the team stated. September is typically one of the most active months of the hurricane season, which begins officially on June 1 and ends on Nov. 30. Warm water is one of the many elements included in the forecast that influence storm formation. "We have seen some of the lowest pressure readings on record in the tropical Atlantic during August. Water temperatures in the tropical Atlantic remain at above-average values. A combination of these two factors typically lead to an active September," said Phil Klotzbach, lead author of the hurricane forecast. June and July were very active months this season, with three named storms forming during that period: Bertha, Cristobal and Dolly. Bertha became the longest-lived July storm on record, while Hurricane Dolly made landfall in south Texas as a Category 2 storm. August saw slightly above-average activity largely due to Gustav, which became a major hurricane in the northwest Caribbean last week. Gustav struck Haiti, Jamaica and Cuba before barreling toward the U.S. Gulf Coast. It made landfall southwest of New Orleans, largely sparring the city that was so devastated by Hurricane Katrina three years before, almost to the day.

Andrea Thompson
Live Science Contributor

Andrea Thompson is an associate editor at Scientific American, where she covers sustainability, energy and the environment. Prior to that, she was a senior writer covering climate science at Climate Central and a reporter and editor at Live Science, where she primarily covered Earth science and the environment. She holds a graduate degree in science health and environmental reporting from New York University, as well as a bachelor of science and and masters of science in atmospheric chemistry from the Georgia Institute of Technology.