Longer Hurricane Season?

On a calendar, the Atlantic hurricane season runs from June 1 to November 30.

But don't tell that to Zeta.

The hurricane didn't even begin until December 30th, finally ending a record setting season of 27 named storms.

The first hurricane in the Eastern Pacific -- Adrian -- came only six days into the season, slamming into El Salvador, and killing at least 29 people.

Scientists say it may be part of a trend in which the hurricane season has become longer as the number of days between the first and last storms increase.

"Since 1915, the length of the season has increased by about 5.5 days per decade," said Peter Webster, an atmospheric scientist leading ongoing research into hurricanes at the Georgia Institute of Technology.

It doesn't sound like much, but Webster said it means the season has lengthened by about 50 days in that period.

The reason, said Webster, is that the world's oceans warming earlier and cooling later, sustaining conditions that favor hurricanes. A hurricane needs water that is 82 degrees Fahrenheit to form.

"The season is lengthening by virtue of the increase in sea surface temperatures and those increased temperatures lasting longer," said Webster.

Scientists said the world's oceans have warmed by about 1 degree in the last century, and most agree that human-caused global warming brought on by the burning of fossil fuels is to blame.

Other recent studies -- including one co-written by Webster and colleague Judith Curry -- have suggested a link between warming sea-surface temperatures and increased intensity of hurricanes, including a doubling in Category 4 and 5 storms (which pack winds greater than 155 mph) since 1970.

Webster and Curry met Wednesday with Florida Gov. Jeb Bush to brief him on what they say will be a very busy hurricane season, though it's not known exactly how long this season will last.

"It's a concern," said Webster, "because a Christmas hurricane is not the type of thing we like to think about."