The Hawaiian hurricane season has kicked into gear this week, with two hurricanes midway between Hawai'i and Mexico, and two more tropical disturbances behind them.

"All of a sudden, it's become quite an active period," said Jim Weyman, director of the Central Pacific Hurricane System.

The nearest storm is Hurricane Jova, which at its current pace is probably still a week away from the Islands. It's still too far away to predict whether it will have significant winds a week from now or even whether it will pass through the Islands or move safely to the north or south, Weyman said.

He urged residents to be alert to the weather systems without going into overload.

"We're talking about a system (that has the potential to reach the Islands) seven days from now. My fear is that people could be tiring of it just when they should be paying attention," he said.

The weather service won't have a forecast of any specific threat to the Islands for several more days.

Jova, moving steadily westward, could be within 500 miles of the Big Island by the middle of next week.

About 720 miles east of Jova and following a similar track is Hurricane Kenneth. It is far enough from Jova that the two are not likely to interact, Weyman said.

As of yesterday, Hurricane Jova was centered about 1,400 miles to the east and about 720 miles south of the Big Island, with maximum wind speeds of about 84 mph. A National Weather Service computerized forecast shows the storm beginning to move in a more northwesterly direction beginning tomorrow and to continue on that track through the middle of next week.

Forecasters expect Jova to cross 140 degrees west longitude — the boundary between the eastern Pacific and central Pacific — by tomorrow.

"That's significant because when it crosses the 140-degree mark, it will be the first hurricane since late August 2003 in the Central Pacific," Weyman said.

The forecast for Jova shows its winds diminishing to about 67 mph by the middle of next week, but Weyman cautioned that the storm's direction and intensity could change drastically over the next four or five days.

Nonetheless, he said he has told Hawai'i County Mayor Harry Kim that the Big Island should brace for storm surf.

"It's kind of aimed at the Big Island right now and the wind is pushing a lot of water in that direction. But it really is very early and there's certainly a possibility the direction could change," Weyman said.

Hurricane Kenneth was roughly 1,800 miles away, and if it continues westward, it could enter the Central Pacific by midweek. Behind Kenneth and Jova are two tropical disturbances, both of which have the potential to grow into tropical cyclones, the weather service said.

"Overall, our hurricane season has been very quiet this year," Weyman said. "We've had one weak tropical disturbance so far, at the beginning of August, that lasted a day or two."

This week, that peacefulness ended.

"Even with the large amount of uncertainty (about the course that hurricanes Jova and Kenneth will take), we need to be very prepared for the eventuality that one of them might hit us," Weyman said.

Reach David Waite at dwaite@honoluluadvertiser.com.