After one of the quietest stretches on record during the heart of the Atlantic hurricane season, activity is showing signs of a late surge. Between Tropical Storm Fernand’s formation on Aug. 23 and Hurricane Gabrielle’s development on Sept. 16, no named storms appeared — a rare calm during what is typically the peak of the season. The last time a similar lull occurred was in 1992.
Forecasters now warn the season may be regaining momentum. The National Hurricane Center is monitoring two additional disturbances, one of which could track toward the U.S. East Coast. In recent years, late-season storms have become more common, with October historically delivering destructive events such as Hurricane Hazel in 1954 and Superstorm Sandy in 2012.
On average, the Atlantic Basin produces three named storms and two hurricanes after Sept. 22. But over the past five years, that average has more than doubled, with about seven tropical storms forming and four reaching hurricane strength. Scientists attribute the increase partly to better monitoring technologies but also to atmospheric and oceanic conditions that have favored storm formation.
This year’s lull was likely influenced by upper-level warmth and Saharan dust, both of which suppressed storm development. Recently, however, the atmosphere has moistened and circulation patterns have become more favorable. Cooler conditions in the tropical Pacific may also be reducing wind shear, which can otherwise disrupt storm growth in the Atlantic.
Researchers point to broader cycles of hurricane activity lasting decades, with the current “warm phase” that began in the mid-1990s fueling more frequent and stronger storms. Climate change may also be shifting the traditional storm calendar, pushing peaks later into the season and intensifying rainfall and winds.
For the Mid-Atlantic and Northeast, the trend raises concern. Late-season storms often track farther north, threatening areas that historically have faced devastating impacts. With waters still warm and the atmosphere becoming more supportive of storm development, forecasters caution that the next several weeks could be unusually active.
Source: The Weather Channel