U.S. government forecasters are predicting at least half a dozen tropical cyclones will form in the Atlantic this year, though it's possible El Niño will prevent any of them from becoming major hurricanes.
Six to 11 tropical storms are expected under a National Oceanic and Atmospheric Administration forecast for this year's hurricane season, which runs June 1 through Nov. 30. Three to six of them could become hurricanes, with maximum sustained winds of at least 74 mph, and of those as few as zero or as many as two are expected to become major hurricanes with winds of at least 111 mph.
Those estimates are slightly below normal, with a dozen named storms and half a dozen hurricanes in an average season. NOAA predicts 70 percent odds the season's tallies will end up below normal, the highest such odds since 1998, the agency's Administrator Kathryn D. Sullivan said Wednesday.
But Sullivan and Federal Emergency Management Agency officials nonetheless urged coastal residents to prepare for the possibility of a storm strike. When Hurricane Andrew struck Florida in 1992, for example, it came amid a below-normal season.
"We've got to be ready for whatever comes," Sullivan said in a teleconference with reporters. "It's not a question of how many pitches [Mother Nature] might throw; it's a question of how ready we can be for any pitch that comes to our strike zone."
NOAA is using a new high-resolution hurricane model and introducing new forecast graphics of storm surge threats to help the nation prepare.
El Niño tends to suppress tropical cyclone development because it creates increased wind shear, when wind speeds and direction vary at different altitudes, and promotes a sinking motion in the atmosphere, Sullivan said. The climate phenomenon tied to Pacific Ocean temperatures began in February and is expected to last through the end of the year.
NOAA's forecast echoes others already issued by AccuWeather.com and the Tropical Meteorology Project at Colorado State University, which also said El Niño will likely suppress storms.
If the forecasts hold true, it would be a second consecutive below-normal season but only the fourth since 2000.
But forecasters emphasized preparation, saying it only takes one storm strike to cause deaths and property damage.
"It all comes down to being prepared – prepared to leave, if necessary," said Joseph Nimmich, deputy administrator of FEMA. The fact that it has been years since the U.S. was last struck by a major storm "creates a great deal of concern that we've become complacent," he said.
A major hurricane has not made landfall in the United States since Wilma in 2005. Superstorm Sandy was a Category 1 hurricane as it approached the eastern seaboard in 2012 but was not technically a tropical cyclone when it made landfall.