HONOLULU, Aug 14 (Reuters) - Hurricane Flossie weakened on Tuesday before it approached the waters off Hawaii, where residents braced for high winds and surf and torrential rain after an overnight earthquake jolt.
Officials on the island of 160,000 people declared a state of emergency as of Monday, closing schools and opening shelters as Flossie passed near its southeast shore.
Known as "the Big Island," Hawaii is the largest in the U.S. Pacific Hawaiian island chain, which has not been hit by a hurricane in 15 years. Forecasters expected Flossie to approach the islands, but not make landfall in the U.S. state.
A 5.4 magnitude earthquake shook the volcanic island on Monday evening, but no injuries or damage were reported.
Wind gusts of up to 50 miles (80 km) per hour, surf as high as 25 feet (8 meters) and thunderstorms were forecast for Tuesday as Flossie kept on a course that would take it just south of the state, the National Weather Service said.
The weather service said it was unlikely the hurricane would hit the state directly, but continued to urge caution.
"The big problems they’re anticipating are heavy rainfall, minor flooding and some road flooding," said Dave Curtis, State Civil Defense public information officer. "The surf could be a big problem."
Southern areas of the island are expected to be hit hardest, with 5 to 10 inches (13-25 cm) of rain.
Early Tuesday, Flossie’s sustained winds had slowed to 110 miles per hour (177 kpm) with higher gusts, at the top of the range for a Category 2 storm, or one capable of inflicting moderate damage. The storm had been a more powerful Category 4 on forecasters’ five-step scale of hurricane intensity.
Hurricane force winds could be felt 40 miles (65 km) from the storm center, enough to keep the island under a hurricane watch and a tropical storm warning, both of which were put in effect by the weather service Monday.
As of early Tuesday morning, Hurricane Flossie was about 390 miles (630 km) southeast of Honolulu, where oil refineries were operating normally but preparing for heavy rain and high winds in the next 12 hours.
Hawaii Gov. Linda Lingle proclaimed a state of emergency on Monday for the island of Hawaii and an advance team from the Federal Emergency Management Agency is already in Honolulu, Curtis said.
Residents of the Big Island were urged to stock up on food and water.
The last time a hurricane hit Hawaii was in 1992, when Iniki caused six storm-related deaths and an estimated $2.4 billion in damage, mostly to the island of Kauai. (Additional reporting by Erwin Seba in Houston)