(Updates with death, details)

By Michael Peltier

CAPITOLA, Fla., March 7 (Reuters) - Tornadoes cut through Florida and Georgia on Friday, destroying homes, felling trees and power lines and killing one person as a record series of winter tornadoes continued to pound the United States.

The National Weather Service had reports of at least 12 tornadoes that flipped cars, damaged homes and interrupted power supplies in northern Florida and southern Georgia.

A 62-year-old woman was killed when a tree fell on her mobile home in a twister that ripped through Lake City, Florida, damaging or destroying 50 homes and a dozen businesses, Columbia County emergency management spokesman Harvey Campbell said.

Sixteen people suffered minor injuries and a man died when he tried to hook up a power generator after the storm knocked out electricity to as many as 16,000 people.

"It's pretty devastating. Lots of trees damaged, substantial power pole damage, lots of homes that have been reduced to brick and wood," Campbell said.

Florida resident Joe Thornton said he had left for work when he got a call a tornado had ripped through his house in Capitola, near the state capital, Tallahassee.

He returned home to find pieces of his neighbor's metal roof wrapped around his trees. His mules, Curly and Ella, were covered in grass and broken twigs and were grumpy but unhurt.

"It doesn't take but one of these tornadoes to make a lifetime of premiums worthwhile," Thornton said. "I feel blessed we're all OK."

Jail inmates were put to work cutting up ancient live oak trees snapped in half by the windstorm that residents said swept through in a flash.

"I got up to go to the bathroom and by the time I was done it was over," said Capitola resident Brett Winchester.

The weather service's Storm Prediction Center counted 368 tornadoes in January and February, far above the three-year average of just under 60 for the two winter months.

A swarm of twisters in early February killed at least 57 people in four states, the deadliest onslaught in two decades.

Ferocious storms that can spin up winds of more than 300 mph (500 kph), tornadoes can occur at any time of the year but the season rarely picks up until March.

The early spike in tornado activity was due to peculiar weather patterns sending successive wave troughs across the United States, said Greg Dial of the Storm Prediction Center. "These patterns don't last forever," he said.

CLIMATE CHANGE?

Some climate experts say it would be reasonable to see an earlier start to the tornado season as a result of global warming, but not necessarily more tornadoes overall as the end of the season would also occur earlier.

About 800 twisters are recorded every year in the United States, most in the "Tornado Alley" Plains area between the Rocky and Appalachian mountains. They kill on average 80 people each year in the United States.

Increased tornado activity has also been associated with the La Nina weather phenomenon, an unusual cooling of waters in the equatorial Pacific that occurs every few years, said Jeff Masters of the Weatherunderground Web site, in a recent blog. (Additional reporting by Michael Christie; Editing by Jane Sutton and Peter Cooney)

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