There were 26 named tropical storms in 2005; hurricanes Katrina, Rita and Wilma were the most powerful seen in the Atlantic Basin. Tropical Storm Epsilon was still churning in the Atlantic on Wednesday.

Katrina, which hit just east of New Orleans in late August, was, in financial terms, the most destructive hurricane in history. Over 1,000 deaths are attributed to the storm. Hundreds of thousands of people were displaced. Oil and gas production was disrupted and refineries and natural gas production plants were shut.

After Katrina, Rita struck western Louisiana in September. Because of the storms, 36.5 percent of US Gulf offshore oil production and 30 percent of natural gas output remained shut as of Wednesday.

SEARCHING PATTERNS

Six months before the 2006 Atlantic hurricane season officially begins on June 1, forecasters are looking at historical weather patterns for indications about the season's severity.

"This far ahead of the season, we really can only talk about two things: the multi-decadal cycle and El Nino formation," said Michael Schlacter, chief meteorologist for Weather 2000 Inc.

A multi-decadal cycle lasts an average of 25 years, and during that period, tropical storm activity is usually above or below the average 10 named storms a year.

The current multi-decadal cycle began in 1995, Schlacter said.

In eight of the 10 years between 1995 and 2004, the number of hurricanes was above average, said Frank LaPore, spokesman for the US National Hurricane Center.

"We're on an upcycle," LaPore said. "In 1970s, 1980s and halfway through the '90s, we were below average."

El Nino conditions occur when trade winds weaken in the Pacific Ocean allowing warmer waters to migrate east from the western Pacific. El Nino also causes winds across the Gulf of Mexico which shear apart hurricanes

"A major El Nino is a bad thing for the hurricanes," Schlacter said. "We do not see an El Nino taking place."

A DIFFERENT CYCLE

Hasling looks at a different cycle that averages 10 years in length. The next cycle is expected to begin in 2006 when sunspot activity is expected to be at a minimum for the first time since 1995.

The sunspot activity is not a trigger for the storms but an indicator of a new cycle, she said, which is driven by the orbit of the solar system around the sun.

Another year that saw the start of a 10-year cycle was 1933, which produced 21 named storms, the most active year until 2005.

Based on comparisons with previous years when sunspot activity was at a minimum, there is a 90 percent chance US Gulf offshore oil and natural gas production areas will be struck by a storm, Hasling said.

The US East Coast from Georgia to North Carolina also has a 90 percent chance of a storm striking there, she said.

Hasling said 11 named storms are expected next year with five of them being hurricanes.

"This far out, I think all you can say is the Atlantic Basin will be much more active," Schlacter said.