By Cheryl Pellerin
Washington File Staff Writer

Washington - With the peak of the 2006 Atlantic hurricane season approaching, experts from the U.S. National Oceanic and Atmospheric Administration (NOAA) have confirmed their prediction for an above-normal number of storms.

For the full 2006 season, which ends November 30, NOAA projects a total of 12 to 15 named storms, of which seven to nine will intensify to hurricanes, and three or four of these could become major hurricanes—rated at category 3 or higher.

The Saffir-Simpson Hurricane Scale is a 1 to 5 rating based on hurricane intensity. A category 3 hurricane has winds of 178 to 209 kilometers per hour, and storm surge is generally 2.7 to 3.6 meters above normal.

Hurricane Katrina was a category 4 storm when it hit the north-central U.S. Gulf Coast in August 2005, with winds between 210 and 249 kilometers per hour. It was the costliest and one of the deadliest hurricanes in U.S. history, and the sixth-strongest Atlantic hurricane ever recorded.

NOAA’s current forecast is slightly lower than the outlook the agency issued in May, but it is above the seasonal average of 11 named storms, six hurricanes and two major hurricanes. (See related article.)

So far in 2006, three named tropical storms – Alberto, Beryl and Chris - have occurred but none became hurricanes.

“While the beginning of this hurricane season has been relatively calm compared to last year,” NOAA Administrator Conrad Lautenbacher said during an August 8 press conference, “it does not mean we are off the hook.”

The peak period of hurricane season is from mid-August through October, he added, “and it's important that all citizens who live along our coasts, in areas that may be prone to hurricanes ... have an emergency plan and [are] able to execute that plan on warnings of severe storms.”

HURRICANE FORMATION

According to Gerry Bell, NOAA's lead seasonal hurricane forecaster, major climate factors expected to influence 2006 storm season activity are the ongoing multidecadal signal, which produces wind and atmospheric pressure patterns favorable to hurricane formation, and continuing warmer-than-normal sea surface temperatures.  NOAA attributes the same factors to the current active Atlantic hurricane era that began in 1995.

Bell said conditions were favorable in 2005 for early season storm development.

"La Niña-like convection in the central equatorial Pacific during June and July of 2005 contributed to the development of numerous early-season storms," he added. "Conditions this year reflect a more typical active season, with peak activity expected during August-October."

La Niña is characterized by unusually cold ocean temperatures in the eastern equatorial Pacific. This is in contrast to El Niño, which is characterized by unusually warm ocean temperatures in the equatorial Pacific.

NOAA's seasonal outlook does not specify where or when tropical storms and hurricanes could strike.

"Science has not evolved enough to accurately predict on seasonal timescales when and where these storms will likely make landfall," Bell said.

"Exactly when and where landfall occurs is strongly controlled by the weather patterns in place as the storms approach land,” he added. “These weather patterns generally cannot be predicted more than several days in advance."

"As we approach the peak of the hurricane season, our message remains the same, be informed and be prepared," said Max Mayfield, director of the NOAA National Hurricane Center in Florida.

"Preventing the loss of life and minimizing property damage from hurricanes are responsibilities shared by all,” he added. “Remember, one hurricane hitting your neighborhood is enough to make it a bad season."

The 2006 Atlantic Hurricane Outlook and additional information on hurricanes are available at the NOAA Web site.