U.S. government forecasters announced Thursday they expect three to six major hurricanes from an above-average Atlantic storm season.
No major hurricane has made a U.S. landfall in five years, but the forecasters warned U.S. coastal residents that odds are they can't expect a sixth straight year without a major landfall on either the Atlantic or Gulf coast.
As many as 18 named tropical storms may develop during the six-month Atlantic hurricane season that begins June 1, according to forecasters at the National Ocean and Atmospheric Administration. Six to 10 of those storms could strengthen into hurricanes with top winds of at least 74 mph, the agency said. Three to six could become major hurricanes, with maximum winds of 111 mph and up.
Last year's hurricane season was one of the busiest on record with 19 named storms, including 12 hurricanes. The 2011 season was not expected to be as extreme, partly because ocean temperatures were only 2 degrees warmer than normal, instead of 4 degrees warmer as they were last year, said NOAA administrator Jane Lubchenco.
"We still expect that to support an above-average hurricane season," Lubchenco said.
Lubchenco also used the occasion to point to the importance of NOAAs satellite program.
"Satellites are a must-have when it comes to being prepared and detecting and tracking dangerous tropical weather," she said. "Not having satellites and not applying their latest capabilities could spell disaster."
She said there's a very real possibility that could happen.
"The future funding for our satellite program is very much in limbo right now," she said.
Already, Lubchenco said, the agency has been forced to delay the launch of a critical satellite. It would have traveled in a polar orbit, beaming down information for weather and climate forecasts. As a result, when the current satellite doing that job stops working there will be no replacement.
"We are likely looking at a period of time a few years down the road where we will not be able to do severe storm warnings and long-term weather forecasts that people have come to expect today," she said.
And Lubchenco said satellites aren't just for hurricanes.
"For example our ability to do a five-day heads-up about the severe tornadoes that hit a couple of weeks ago was a direct consequence of us having polar orbiting satellites," she said.
Lubchenco's comments come after years of warnings by groups including the National Academy of Sciences that the U.S. needed to replace many aging satellites used to study and monitor the Earth.
Lubchenco also said that "La Nina," a Pacific Ocean weather phenomenon, was expected to dissipate early in the summer before the season's peak, typically from August to October.
La Nina is an unusual cooling of the Pacific waters near the equator. When it's in effect, wind shear over the Caribbean Sea and tropical Atlantic decreases, meaning that tropical storms have a chance to develop and strengthen before being ripped apart.
Forecasters say La Nina helped make the 2010 season so active. The opposite El Nino phenomenon, which warms Pacific waters near the equator and increases wind shear over the Atlantic, helps suppress storm development.
Nevertheless, atmospheric and marine conditions indicating a high-activity era that began in 1995 continue, and lingering La Nina impacts such as reduced wind shear are conducive to a busy storm season, said Gerry Bell, lead seasonal hurricane forecaster at NOAA's Climate Prediction Center in Washington.
"We don't think La Nina will be a player for much of the season, but that's really secondary," Bell said. "Conditions are already starting to be in place and we expect them to develop, and that's why we expect an active season to be likely."
'Cannot Count On' Luck
No major hurricane has made a U.S. landfall since Category 3 Hurricane Wilma struck Florida in 2005, though Hurricane Ike caused extensive damage in September 2008 when it roared ashore in Galveston, Texas, as a strong Category 2 storm with top winds around 109 mph. After peaking as a Category 4 storm near the Turks and Caicos Islands, Ike caused $10 billion in damage in Texas, Louisiana and Arkansas, making it the third-costliest storm after Hurricanes Katrina in 2005 and Andrew in 1992, according to the National Hurricane Center.
Scientists said coastal residents can't expect their luck to hold.
"The U.S. was lucky last year. Despite an above-normal season, we did not have significant damage from these storms on U.S. land. The winds that steer where storms go kept them away from our coastlines," Lubchenco said. "We cannot count on having the same luck this year."
Federal Emergency Management Agency Administrator Craig Fugate urged residents from Texas to Maine to develop disaster plans and determine whether they live in evacuation zones.
"Far too many people will not be prepared and will try to get ready in the last minutes when a hurricane is threatening their community and not have enough time," Fugate said.
Forecasters name tropical storms when their top winds reach 39 mph. The first named storm of the 2011 season will be Arlene.
The seasonal average is 11 named storms, six hurricanes and two major hurricanes.
In April, Colorado State University researchers predicted 16 named storms would form this season, with five strengthening into major hurricanes.
Hurricane season ends Nov. 30.
NPR's Jonathan Hamilton contributed to this report, which includes material from The Associated Press Copyright 2011 National Public Radio. To see more, visit http://www.npr.org/.