Hurricane season over

The relatively uneventful 2006 Atlantic Basin hurricane season ended yesterday.

A busy hurricane season had been predicted in the Atlantic this year after last year’s record 28 named storms and 15 hurricanes. The United States’ National Oceanic & Atmospheric Administration had predicted 13 to 16 named storms this year; eight to 10 hurricanes; and four to six major hurricanes.

In the end, however, hurricane season was even less active than average, with only nine named storms (11 is average), five hurricanes (six is average) and two major storms of Category 3 or higher (two is average). None of the major hurricanes reached Category 4 or 5 in 2006, and in fact they only remained Category 3 hurricanes during parts of three days.

The nine named storms were the fewest in the Atlantic since 1997; the five hurricanes were the fewest since 2002; and the two major hurricanes were the fewest since 1997.

The Cayman Islands was spared completely from tropical systems, but it did have one scare from Hurricane Ernesto in August. That storm was tracking westward through the Caribbean on a direct course to impact the Cayman Islands as a strong tropical storm or a week Category 1 hurricane. However, Ernesto stalled near Haiti and eventually headed northwest through the passage between Jamaica and Haiti and hit eastern Cuba as a tropical storm instead.

Ernesto became one of only three tropical systems to make landfall in the United States in 2006. Tropical Storm Alberto came ashore on the Florida panhandle in June and Tropical Storm Beryl passed over Nantucket Island, Massachusetts in July.

Ernesto, which made landfalls in Florida as a tropical depression and in North Carolina as a tropical storm, caused over $100 of damage in the United States, the most destructive of any of the 2006 hurricanes. Ernesto was also responsible for seven deaths; two in Florida and five in Haiti.

The 2006 Hurricane season started early, with Alberto forming on 11 June. But the tropical system activity also ended early, with Hurricane Isaac forming on 28 September and dissipating by 2 October.

One of the probable reasons cited for the less-than-predicted activity during the hurricane season was the rapid and unexpected formation of El Niño conditions in the Pacific Ocean. El Niño, which is a rising of water surface temperatures in the Pacific, tends to curtail hurricane formation in the Atlantic Basin.

Other possible reasons the hurricane season produced less activity that predicted include higher wind shear, especially during part of August; dry air in the region; and an increase in Saharan dust storms moving off of Africa.

In addition, upper level wind currents were such during August and September that every tropical system that formed after Ernesto curved northward toward the central Atlantic, threatening only Bermuda on several occasions.

Tropical storm systems can form any time of the year in the Atlantic Basin. Historic statistics, however, show most occur during the established six-month hurricane season between 1 June and 30 November every year.