Hilo, Hi, 08/13/2007 -- A hurricane watch has been issued this morning for Hawaii County and coastal waters adjacent to the Big Island, the National Weather Service said.

At 5 a.m., Hurricane Flossie was continuing to maintain its strength. The National Weather Service said its closest point of approach will be 100 miles south of south point on Tuesday, when Flossie is expected to be a Category 3 hurricane.

Hurricane Flossie is currently packing 135 mph wind.

At 5 p.m. yesterday, the storm was 675 miles southeast of Hilo and about 875 miles from Honolulu.

A change of course in the unpredictable storm could bring it closer to land.

Everyone in the Hawaiian Islands is urged to continue monitoring the progress of Hurricane Flossie, the Central Pacific Hurricane Center said in a statement. A northward shift in the track could potentially bring hurricane conditions to the Big Island.

Emergency workers mobilized yesterday to prepare, Big Island Mayor Harry Kim said. You always prepare for the worst-case scenario and hope for the best, he said.

Two Air Force WC-130 hurricane tracker planes were dispatched from Mississippi and flew into the storm to gather measurements this afternoon, said Roy Matsuda, lead forecaster at the Honolulu office of the National Weather Service.

The weakening process looks much slower. It will keep more of its juice, Matsuda said. It won't be a tropical storm. It'll be a weak or minimal hurricane.

Even though the eye of the storm may miss the Islands, Flossie could still bring strong wind and heavy rain ashore, forecasters said.

The southeastern shore of the Big Island could see waves of 8 to 12 feet, with the surf rising tomorrow.

Some shoppers on the Big Island were taking no chances, loading up on essentials.

They're buying a lot of water, batteries and propane, said Burt Takata, an assistant manager for Wal-Mart in Hilo. I guess they're getting ready just in case.

At the KTA Super Store in Keauhou, shoppers appeared to be taking the approaching storm in stride.

It's a busy Sunday afternoon, but nothing unusual, said assistant front-end supervisor Pat Murasaki. I've heard people talking about the storm, but I don't think they're buying any more than usual.

On O'ahu, several store managers said they haven't seen a big increase in storm-related shopping.