US Expects Busy Hurricane Season, But no Record
Date: 23-May-06
Country: US
Author: Jim Loney
The season is expected to produce 13 to 16 named storms, with eight to 10 becoming hurricanes, of which four to six could become "major" hurricanes of Category 3 strength or higher, the National Oceanic and Atmospheric Administration said in its annual forecast.
The most damage is caused by storms that reach Category 3, with winds of 111-130 mph (178-209 kph), or higher on the five-step Saffir-Simpson scale of hurricane activity.
US National Hurricane Center director Max Mayfield said people in hurricane zones should not focus on the numbers.
"It just takes that one hurricane over your house to make for a bad year," Mayfield said at a news conference at the hurricane center.
Scientists were way off the mark in their forecasts of last year's hurricane season, which caused more than US$100 billion in damage in the United States. The official season runs from June 1 to Nov. 30.
The 2005 season spawned an unprecedented 28 tropical storms, of which 15 became hurricanes. NOAA had predicted 12 to 15 tropical storms, of which it said seven to nine would be hurricanes. Seven of last year's hurricanes were considered "major," while NOAA had predicted only three to five would reach that level.
A record four major hurricanes hit the United States, including Katrina, which devastated New Orleans, killed 1,300 people and caused US$80 billion in damage. Rita slammed into Louisiana and Texas, and Wilma briefly became the most intense Atlantic hurricane ever recorded.
Forecasters say many factors point to a busy hurricane season, including warm sea surface temperatures, which fuel the big storms, as well as weaker easterly trade winds and expanding upper-level easterlies, which lowers the "wind shear" that can stop storms from forming or tear them apart.
"There is a silver lining in this year's forecast. That is the fact that the weak 'La Nina' condition in the equatorial Pacific has dissipated. It will not be an issue in this hurricane season," NOAA administrator Conrad Lautenbacher said.
La Nina is an occurrence of unusually cool water in the Pacific that can enhance Atlantic storm activity.
Unfortunately for residents of the Atlantic region, La Nina's opposite number, El Nino, a warm-water phenomenon in the eastern Pacific that tends to dampen hurricane activity in the Atlantic, is not on the radar either.
The average six-month hurricane season has 10 tropical storms, of which six strengthen into hurricanes when their maximum sustained winds reach at least 74 mph (119 kph).
US hurricane experts say a sharp rise in Atlantic storm activity since about 1995 is related to a natural shift in climatic conditions and sea surface temperatures in the Atlantic that is expected to last from 15 to 40 years.
Some climatologists however say there are indications that human-induced global warming could be increasing the average intensity of tropical cyclones, although there is no evidence to date that it is affecting the number of hurricanes.