HOUSTON  – Private forecaster AccuWeather.com said on Wednesday it expects four tropical storms to strike the U.S. coastline during the 2009 Atlantic season, which begins June 1, compared with eight last year.

AccuWeather's Chief Long-Range and Hurricane Forecaster Joe Bastardi said the greatest risk this year may be to the U.S. East Coast, but a storm in the oil-rich Gulf of Mexico could not be ruled out.

"I do think the Eastern Seaboard and the Canadian Maritimes will need to watch more than normal," Bastardi told Reuters. "The Gulf of Mexico is much less active than in the past, but that doesn't mean we can't get something together in the Gulf."

Bastardi's weather forecasts can have tremendous sway over U.S. energy market traders' outlook for national supply and demand.

Bastardi forecasts three of the storms striking the U.S. coast to be hurricanes with one a major hurricane packing winds of at least 111 miles per hour, rated as a category 3 on the five-step Saffir-Simpson scale.

Accuweather's forecast is in line with those of other metrologists, which expect reduced activity compared with 2008 when storms shut offshore oil platforms and onshore refineries for weeks.

Offshore production in the U.S.-regulated areas of the Gulf of Mexico provide a quarter of national crude oil supply and 15 percent of natural gas, while 43 percent of the country's refining capacity lies along the shores of Texas, Louisiana and Mississippi.

Among the factors forecast to reduce the number of storms is a weak El Nino weather pattern expected to form in the mid to late hurricane season, Bastardi said.

El Nino weather patterns occur when water temperatures are warmer than normal in the eastern tropical Pacific Ocean. During an El Nino, Atlantic hurricane activity is reduced.

Stronger trade winds across northern Africa are forecast to increase dust and dry air blowing into the Atlantic, reducing temperatures where storms form.

Cooler water temperatures in the tropical Atlantic may reduce the number and intensity of storms, but those moving to the north and east may have more time to strengthen, he said.

For the entire Atlantic season, Bastardi predicts 13 named storms including eight hurricanes with two of those rated as major storms of category 3 or higher.

Colorado State University's Tropical Metrology Project issued a forecast at the end of December calling for 14 named storms including seven hurricanes three of which are expected to become category 3 or stronger.