Accuweather sees above-average '11 hurricane season

"We feel that this season, there will be a higher potential for impacts across the southern part of the Basin into the Gulf of Mexico during the first part of the season," said Accuweather lead metrologist Paul Pastelok. "This higher potential for impacts shift farther north into the southeast U.S. during the latter half of the season."

On the Gulf Coast, the greatest threat will be to the Texas and Louisiana coasts in the early part of the season, according to Accuweather's forecast, released on Wednesday.

For 2011, Accuweather forecast 15 named tropical storms, eight hurricanes with three of them major hurricanes of a category 3 or above on the Saffir-Simpson scale of storm intensity.

About 25 percent of U.S. crude comes from U.S.-regulated areas in the Gulf of Mexico and over 40 percent of U.S. refining capacity stretches from Corpus Christi, Texas, to Pascagoula, Mississippi.

The Atlantic hurricane season begins June 1 and ends November 30.

An average Atlantic hurricane season produces 10 named tropical storms, six hurricanes with two of them considered major.

The 2010 season was very active with 19 named storms, 12 hurricanes and five major hurricanes, none of which struck the U.S. coast line.

Pastelok said the United States was unlikely to be spared for a second year.

"It looks like we're going to have more impact on the mainland of the U.S. coming up this year compared to last year," he said. "We had a lot of storms last year, but not a lot of impact (on the U.S.)."

The main factors affecting this year's forecast are the positions of high pressure systems over the Azores and Bermuda, a weakening La Nina system in the Pacific, dust coming off Africa and sea-surface temperatures.

The La Nina anomaly, which is a cooling of surface waters in the eastern and central Pacific, causes lower wind shear across the Caribbean and tropical Atlantic where tropical storms form.

The current La Nina is weakening which could result in high wind shear that could disrupt tropical storms, Pastelok said.

Dust coming off Africa indicates dry air, which inhibits the formation of tropical storms.

"Current projections on the weather pattern over Africa for this coming tropical season suggests there will be episodes of dust affecting development, but no more than normal," Pastelok said.

"This will help to maintain warmer-than-normal water temperatures across most of the Atlantic Basin," he said.

The Atlantic Ocean is currently in a warm period which tends to encourage the formation of more storms in the area.

(Reporting by Erwin Seba; Editing by John Picinich)