TROPICS SEE ONE OF THE SLOWEST SEASONS IN THE PAST 10 YEARS

By James Hudgins

 

Despite seeing an early season tropical depression form near the end of May, the Atlantic tropical hurricane season will be remembered as having the fewest number of storms since 1997.  So far through mid October, there have been only 8 named storms (Fig 1), 2 of which were hurricanes, and 6 tropical storms. There were also a couple additional tropical depressions that never reached storm status. However both of the hurricanes were major (Category 3+) hurricanes, with Bill reaching category 4 status southwest of Bermuda in mid August, while Fred briefly touched category 3 levels just west of the Cape Verde islands in early September before quickly weakening.  Other tropical storms, Ana and Erika impacted the islands of the Lesser Antilles to some degree, while Claudette was the only U.S. landfall, crossing the western Florida panhandle in mid August.

Although the numbers were below the 50 year averages of 10 named storms, and 6 hurricanes per season, some records were established. These would include Tropical Storm Ana which formed on August 12th making it the latest date since 1992 that the season’s first named storm had formed so late.  Also Hurricane Fred was the strongest hurricane so far south and east in known data records, as it reached major hurricane status about thirty-six hours after formation, becoming only the third known major hurricane east of longitude 35 degrees West.  In addition despite the lack of many storms, 15 fatalities occurred, with many of these associated with drownings along the East Coast indirectly associated with large swells and rip currents with Bill.

The slow season can be attributed to several factors including fewer tropical waves, dry air over the central and eastern Atlantic, and nearly continuous southwesterly wind shear partly due to El Nino conditions over the eastern Pacific. With similar conditions expected to persist into the end of the Atlantic hurricane season which ends November 30th, a minimal number of additional tropical cyclones are expected from mid October through the end of November.

Tropical Tracks for 2009

Fig 1. Tropical cyclone tracks for 2009 through mid October.