Lian Xie had a white-knuckle moment in April as his top student stepped onto a California stage to present a paper that contradicted all of the heavyweights of hurricane forecasting and their dire predictions of another scary season this year.

There before fellow forecasters assembled for a national hurricane conference, the N.C. State meteorology professor and doctoral student Tingzhuang Yan predicted a far milder season, with only one or two hurricanes striking the East Coast out of five or six forming in the Atlantic Ocean east of the United States.

That flew in the face of other forecasts, including those by the National Hurricane Center, which predicted seven to nine hurricanes -- three or four packing winds of 111 mph or more. After a record-setting 2005 season that produced 28 named storms, including Hurricane Katrina, the nation's worst natural disaster, the higher numbers seemed to be more authoritative.

"Almost everyone was predicting another extremely active year -- all the big names were saying the same thing," said Xie (pronounced ZHWAY). "We were taking a chance, a risk. If we were wrong, everybody would be laughing at me."

Turns out, the upstarts from N.C. State got closer to the bull's-eye than the big boys, finding a trend in piles of data the others overlooked or underplayed. Although hurricane season doesn't officially end until Nov. 30, there have been only nine named storms in the Atlantic Basin, five of them hurricanes.

Only one -- Hurricane Ernesto -- struck the East Coast, making landfall for a second time Aug. 31 as a tropical storm on the North Carolina coast near Oak Island after crossing Florida and strengthening to barely hurricane status. North Carolina was also soaked by Tropical Storm Alberto in June and brushed by Tropical Storm Beryl in July.

None of the main guns of hurricane prognostication predicted the relatively mild season Xie's team foresaw. All of them were forced to repeatedly downgrade their forecasts as the season slowly fizzled and storms spun harmlessly into the North Atlantic, far from the U.S. coastline.

Xie and his fellow researchers, including Dave Dickey, an N.C. State statistics professor, think they've found a key piece of the complex puzzle of climate conditions that help create hurricanes. Looking at the same 100-year database of sea temperatures, winds and cycles between El Nino and La Nina as other forecasters, they noticed a pattern:

The number and intensity of hurricanes forming in the Atlantic and their chances of striking the East Coast seemed to hinge on the difference in water temperatures in the North and South Atlantic. When tropical waters in the North Atlantic were warmer than normal while tropical waters in the South Atlantic were cooler than normal, hurricane activity east of the U.S. coastline increased. So did their chances of striking the East Coast.

That's what happened in 2005, when Xie and his colleagues predicted five to six hurricanes would form east of the United States and two to three would strike the eastern seaboard. The actual number: seven hurricanes and two landfalls on the East Coast. Overall, 15 hurricanes formed during the season, including Katrina and Rita, which barreled through the Gulf of Mexico.

When a flip-flop in these temperatures occurred, with warmer-than-normal tropical waters in the South Atlantic and lower-than-normal temperatures to the north, hurricane activity decreased, as did the chance of an East Coast landfall. That's what happened this year, said Xie, whose team focuses its forecasts on the East Coast, unlike other forecasters who include the Gulf of Mexico and Caribbean Ocean.

The heavyweights, particularly Bill Gray of Colorado State University, lean on other climate factors as well. Gray was one of the first meteorologists to emphasize the importance of the El Nino and La Nina cycles in the Pacific Ocean. When the colder-than-normal waters of La Nina move into the Pacific off the western coast of South America, there is more hurricane activity in the Atlantic Basin. When the warmer-than-normal waters of El Nino move in, Atlantic hurricane activity decreases.

This year, El Nino made an earlier-than-expected appearance, dampening hurricane activity in the Atlantic, said Jeff Orrock, severe weather coordinator at the National Weather Service's Raleigh office. Those higher temperatures in the Pacific helped create strong, upper-level winds in the tropical waters of the Atlantic that sheared the tops off tropical storms.

Other factors also dampened hurricane activity, including huge dust plumes rising from the Sahara desert.

Scattered through the summer were brief windows of opportunity, offering the right combination of weather conditions for a hurricane to strike the United States, Orrock said. Ernesto struck during one of those windows.

"The door was open to bring them in from time to time -- we just lucked out," Orrock said.

Xie doesn't buy this explanation. But he's careful not to brag about the success of his team's hurricane model.

"It's not that we were smarter than everybody else," he said. "If we were truly smart, we would have said, 'It will be an inactive year.' But we were closer to the truth."

(News researcher Lamara Williams-Hackett contributed to this article.)

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