Aug. 22 (Bloomberg) -- Hurricane Bill is forecast today to pass through open seas between the U.S. East Coast and Bermuda as it moves toward the Canadian Maritimes. A tropical storm warning was issued for the southern Massachusetts coast.

The storm had sustained winds of 105 miles (165 kilometers) per hour, making it a Category 2 on the five-step Saffir-Simpson scale, according to the U.S. National Hurricane Center in Miami. It was 430 miles east-southeast of Cape Hatteras, North Carolina and moving north-northwest at about 22 miles per hour, the center said today.

While the hurricane is forecast to eventually curve away from the U.S., a tropical storm warning was issued today for the coast of Massachusetts close to Cape Cod, from Woods Hole to Sagamore Beach, including Nantucket and Martha’s Vineyard, where President Barack Obama and his family are scheduled to travel tomorrow for a week’s vacation. The hurricane should also reach Canadian waters tomorrow.

“It will definitely be a hurricane when it reaches our Maritime waters Sunday,” said Peter Bowyer, a program supervisor at the centre in Dartmouth, Nova Scotia. “At this point, it is still not possible to give all the specifics everyone wants.”

It’s poised to bring as much as 6 inches of rain and hurricane force winds to the Maritimes, the Canadian Hurricane Centre predicted. The provinces are also experiencing the highest tides of the year, so there is potential for a large storm surge if Bill arrives at the wrong time, Bowyer said.

Bermuda on Alert

Bermuda, a British overseas territory, is under a hurricane watch and a tropical-storm warning. The center of Bill is expected to come within about 200 miles, the Bermuda Weather Service said. Troops are on standby as the island faces as much as rain as the Canadian Maritimes.

Bill will raise the tides 3 feet above ground level near the coast of the island, the weather service said.

Large swells from Bill “are affecting the Bahamas and Bermuda and beginning to affect the southeast coast of the United States,” the U.S. hurricane center said. “Large swells will begin to affect much of the remainder of the U.S. East Coast and the Atlantic Maritimes of Canada later today and Sunday. These swells will likely cause extremely dangerous surf and life-threatening rip currents.”

Workers are being evacuated from the Sable Offshore Energy Project, a gas field 125 miles off Nova Scotia, said Margot Bruce-O’Connell, a spokeswoman for Irving, Texas-based Exxon Mobil Corp. The rigs, backed by Exxon and Royal Dutch Shell Plc, were closed for maintenance and the storm won’t affect production, she said.

Refineries Watched

Some refineries in Nova Scotia and New Brunswick may be at risk, including closely held Irving Oil’s Saint John plant that processes about 300,000 barrels of oil a day, according to Olivier Jakob, an analyst with research group Petromatrix GmbH in Zug, Switzerland.

“The marine environment on Sunday and Sunday night is going to be a harsh environment,” Bowyer said. “It is too uncomfortable a scenario to take a chance on.”

The Halifax Port Authority doesn’t expect Bill to interfere with regular ship traffic, Michele Peveril, a spokeswoman for the port, said Aug. 20. Halifax is Canada’s third-largest port behind Vancouver and Montreal, and handles cargo and passenger traffic.

The 2009 hurricane season, which runs from June 1 to Nov. 30, got off to a quiet start before three named storms formed in a period of 48 hours Aug. 15 and 16. Tropical storms Ana and Claudette have since dissipated.

To contact the reporters on this story: Brian K. Sullivan in Boston at bsullivan10@bloomberg.net; Alex Morales in London at amorales2@bloomberg.net.

Last Updated: August 22, 2009 06:06 EDT