By Jane Sutton
MIAMI (Reuters) - Tropical Storm Danny spun in the Atlantic Ocean on Thursday on an erratic path that could take it near the northeastern U.S. coast as a hurricane during the weekend.
Forecasters at the U.S. National Hurricane Center urged residents from the Carolinas northward to New England to monitor the storm in case it lurched to the west.
At 11 a.m. EDT on Thursday, Danny was centered about 550 miles south-southeast of Cape Hatteras, North Carolina. It was wobbling along a northwest track at 13 mph and was expected to curve to the north and then northeast.
That path would take it near New England on Saturday and then over Canada's Atlantic maritime provinces on Sunday. That would put it over Canada's energy-producing region, which exports oil, natural gas and refined products to the U.S. Northeast and elsewhere.
"While the forecast track does not currently show Danny making landfall in the United States, additional motion to the left of the track could bring the center near or over the U.S. eastern seaboard," senior hurricane specialist Jack Beven said in a hurricane center advisory.
Danny had top sustained winds of 60 mph and forecasters said it could strengthen into a hurricane on Saturday. Tropical storms become hurricanes if their sustained winds reach 74 mph.
The forecasters predicted Danny would just barely cross that wind speed threshold on Saturday, becoming the second hurricane of the season, and then start to weaken.
The forecast path would take Danny near the Massachusetts coast, where U.S. President Barack Obama is vacationing with his family on the island of Martha's Vineyard. It could also bring blustery weather to Boston, where Senator Edward Kennedy's funeral is scheduled on Saturday.
Danny is the fourth named storm of the June-through-November Atlantic hurricane season, which has so far been mild in comparison to recent years.
Tropical storms and hurricanes are tracked closely by energy traders concerned about disruptions to oil and gas production in the Gulf of Mexico and Canada's Atlantic region, and by commodities traders for damage to citrus, cotton and other crops.
Pricing of insurance-linked securities, which transfer insurance risks associated with natural disasters to capital markets investors, and can be used to hedge other weather risk exposures, can also be affected by the future path of a storm.
(Editing by Pascal Fletcher and Mohammad Zargham)
