(Updates storm location, details) HAMILTON, Bermuda July 13 (Reuters) - Hurricane Bertha weakened back into a less-menacing tropical storm on Sunday after stalling for a day near the British colony of Bermuda, the U.S. National Hurricane Center said. The top sustained winds of what had been the first hurricane of the 2008 Atlantic storm season slipped to near 65 miles per hour (100 km per hour), below the 74 mph (119 kph) threshold at which tropical storms are classified as hurricanes, the Miami-based hurricane center said. Little change in strength was expected over the next 24 hours and the storm had stalled again after inching its way northwest for a brief period early on Sunday. "The center of Bertha is expected to slowly pass not far to the southeast and east of Bermuda during the next day or so," the hurricane center said. It said the storm's motion could be erratic at times but that it could pass closer to Bermuda, a wealthy mid-Atlantic offshore finance center, than indicated earlier. At one point a "major" Category 3 hurricane on the five-step Saffir-Simpson scale of storm intensity, as Hurricane Katrina had been when it came ashore near New Orleans in 2005, Bertha weakened because of its lack of movement. Its energy had churned up colder waters from beneath the sea surface, depriving it of the warm water that fuels tropical storms. Bermuda, which is also a major tourist resort, has strict building codes and a tropical storm is unlikely to pose any significant threat to its 66,000 people. Few of the shops in Hamilton's retail heart of Front Street had storm shutters up on Sunday and some public beaches were still open despite high storm-related surf. Many islanders said they were looking forward to the arrival of Bertha, as it would bring some much-needed rain after a long drought. As of Friday the island has had just 1.3 inches (3.3 cm) of rain in six weeks, 20 percent below normal. Oil markets had kept a wary eye on Bertha after it formed because of the potential of hurricanes to cause havoc among the oil rigs of the Gulf of Mexico. But the Gulf has not been in Bertha's track for many days. By 2 p.m. EDT (1800 GMT), Bertha was around 190 miles (310 km) south-southeast of Bermuda. Hurricane experts have forecast that the 2008 Atlantic storm season will be average or above average. The long-term average is for 10 tropical storms to form between June 1 and the end of November, of which six become hurricanes. Bertha formed near the Cape Verde Islands off Africa and its development that far east so early in the season is viewed by some hurricane experts as ominous. Storm activity does not usually get into high gear in the Atlantic until August. On one Bermudian beach, 28-year-old English accountant Helen Grimwood took a more sanguine view of Bertha, however. "I am quite excited and interested to see what it will be like," said Grimwood, who arrived in Bermuda just three days ago to start a new job. "I am not worried about it," she said. (Reporting by Michael Christie and Matthew Taylor; Editing by Tom Brown and Cynthia Osterman)
