State civil defense officials aren't taking any chances, advising residents to be prepared.

At 11 a.m. Hawai'i time today, the storm was about 1,300 miles southeast of Hilo and had winds of 85 mph. It was expected to strengthen slightly in the next day and a half, but then weaken as it passed over cooler waters.

"It looks like the system is going to pass well south of the Big Island and all of the other islands," said Bob Burke, a meteorologist with the National Weather Service in Honolulu. "The biggest impact may be some large rough surf."

The Big Island's southeastern shores could see waves of 8 feet to 12 feet, Burke said, with the surf rising during the day on Monday and peaking Tuesday. The island's South Point is the southernmost area of the United States.

Flossie formed as a tropical storm on Wednesday about halfway between Mexico's southern Pacific coast and Hawai'i. It strengthened to a hurricane Friday.

"It's hurricane season. If you haven't thought about preparedness, now is a darn good time to think about it," said Dave Curtis, spokesman for the state Civil Defense Agency. "If this thing fizzles out, so what? Everybody should still be prepared."

Curtis advised residents to have emergency kits, plans, water and food ready.

"We don't know what this storm is going to do yet, but it's certainly acting as a reminder to tell folks, 'Hey. Are you prepared? If not, get prepared. Let's go,"' Curtis said.

Hurricane season runs from June 1 to Nov. 30.

In May, forecasters predicted that Hawai'i and the rest of the central Pacific face a slightly below-average hurricane season this summer, with just two or three tropical cyclones expected because of lower sea surface temperatures.

The islands get an average of 4.5 tropical cyclones a year and one hurricane about every 15 years. Last year, the central Pacific had five tropical cyclones after NOAA predicted two to three.