"We're in a different hurricane era," he told reporters.

NOAA officials could not predict how many of the 2005 storms would hit the US coast, or where and how significant the damage would be. But during an especially active season such as this one, an average of two to three hurricanes can be expected to strike the United States.

The Atlantic hurricane season, which ends on Nov. 30, typically peaks between August 1 and late October.

In May, NOAA predicted this hurricane season would be above normal, with up to 15 tropical storms and 9 hurricanes.

The new forecast, based on atmospheric conditions and warmer-than-usual ocean temperatures, would mean a tie for the record number of tropical storms. The most active season was 21 storms in 1933, according to NOAA.

The alphabet used by the National Hurricane Center to name storms includes 21 letters. If there are 22 storms, it would begin using the Greek alphabet, such as Hurricane Alpha.

UNCERTAIN LINK TO GLOBAL WARMING

NOAA blamed the increase on cyclical conditions, not global warming. Hurricane activity was low from about 1970 to 1994 before a more active cycle began in 1995.

"It's certainly reasonable to expect above-normal hurricane seasons for the next decade or perhaps even longer," Bell said. "It's not a matter of if more hurricanes are going to hit the coast, it's simply a matter of when."

A study published this week in the journal Nature said hurricanes became more destructive in the past 30 years and their growing intensity could be caused by global warming. The report said the duration and wind speed rose by 50 percent.

NOAA said it has detailed hurricane records only since 1945 and lacks data to determine if there is a link to global warming. "We're not convinced that global warming is playing an important role yet, or if at all, in this era of increased activity," Bell said.

In early July, Hurricane Dennis pounded the US Gulf Coast with sustained winds of 120 miles per hour, causing losses estimated as high as $5 billion. Later in the month, Hurricane Emily made landfall in the Gulf Coast about 75 miles south of the US-Mexico border with winds of 125 mph.

So far this year, tropical storms and hurricanes have halted more than 6.14 million barrels of US crude oil production from the offshore Gulf of Mexico. Damage from last year's Hurricane Ivan cut about 45 million barrels of crude output over six months after that storm toppled platforms and damaged undersea pipelines.

The 2004 hurricane season was one of the most devastating recorded. The Atlantic Ocean churned out 15 tropical storms, nine of which turned into hurricanes, and caused billions of dollars in damage to the Caribbean and the United States.

David Johnson, director of NOAA's National Weather Service, said that while coastal communities are at highest risk, Americans living inland also need to be prepared for damaging storms. About half of all hurricane deaths and injuries occur from inland fresh water flooding, he said.

Tropical disturbances and storms typically form off the west coast of Africa, then move west toward the Caribbean and the United States as they strengthen.

Although NOAA declined to forecast where 2005 storms would hit, some private forecasters said the Carolinas may be a target.

Joe Bastardi, a meteorologist with AccuWeather, predicted most remaining storms this year will take a more easterly path than the June and July storms that entered the Gulf of Mexico.