Unusually warm ocean waters and favorable atmospheric conditions are expected to create an above-average number of tropical storms and hurricanes in the Atlantic and Caribbean this season, national weather forecasters predicted.

In its latest outlook, the National Oceanic and Atmospheric Administration said there was a strong likelihood of seven to 11 hurricanes — including three to six major hurricanes with winds of at least 111 mph.


Forecasters cite the convergence of several factors in May that should generate an above-average number of tropical storms over the next six months.

Bolstering their predictions for the formation of strong hurricanes are: reduced vertical wind shear, lower air pressure across the tropical Atlantic and the expected emergence of a strong West African monsoon.


“This year is very similar to the active seasons we’ve been seeing,” said Gerry Bell, lead seasonal hurricane forecaster at NOAA’s Climate Prediction Center in Washington, D.C. Such high activity has been recorded since 1995.

The outlook has proved valuable in predicting how many storms, hurricanes and major hurricanes will develop. However, it does little in the way of predicting destructive storms, said Dennis Feltgen, spokesman for the National Hurricane Center in Miami.


Those predictions typically come only about a week before a storm hits land.

NOAA defines the strength of a season not only by how many storms occur, but also by their duration and intensity, among other measures. Whether the storms make landfall has no bearing, Bell said.


“It only takes one hitting you to make it a really bad year,” he said.

Last hurricane season, for instance, was not considered exceptionally strong by those measures. Only two major hurricanes formed in the Atlantic.


One of them, however, was the devastating Superstorm Sandy.

About two dozen states felt the wrath of Sandy, which eventually grew into a hurricane and merged with another storm front.


It was the deadliest storm to hit the mid-Atlantic and Northeast in 40 years and the second-costliest in the nation’s history, according to the National Hurricane Center report.

At its peak, the storm’s diameter spread about 1,000 miles. At least 147 deaths across the Atlantic basin — including 72 in the United States — were attributed to Sandy.


More than 650,000 homes in the U.S. were damaged or destroyed and more than 8 million customers lost power, the report said.

Sandy showed that residents in coastal regions as well as inland should heed hurricane forecasts and warnings, Feltgen said.


“If you play the odds, you might win, but you might lose,” he said. “And if you lose, you’ll lose big.”

stephen.ceasar@latimes.com