Tropical Storm Ana, churning in the Pacific Ocean, was forecast to become a hurricane bearing 90-mile-per-hour (145-kph) winds as early as Tuesday night, forecasters said, and was on a track that could see it bearing down on Hawaii later this week.

If so, Ana would be the first hurricane to hit Hawaii since Iniki in 1992, although National Weather Service forecasters said it was still too early to predict that it would make landfall on the archipelago.

"Right now the forecast track has it passing just over the southern end of the Big Island, but it's early yet; there are a lot of scenarios," National Weather Service forecaster Kevin Kodama said.

"It could pass right over state, it could move to south or it could move to the north," Kodama said. "The main thing we're trying to get across right now is preparedness."

Kodama said forecast models predicted that Ana could strengthen into a Category 1 hurricane by Tuesday night, bearing maximum sustained winds of 90 miles per hour. He called such a storm "a pretty significant system."

If Ana remains on a track to hit Hawaii it could make landfall by Saturday morning.

Residents were being advised to stockpile food and potable water and to make sure they had an evacuation plan if necessary.

"At this point the best we can do is monitor the situation because we still don't know what, if any, impacts there will be on our island," said John Cummings, public information officer for Honolulu's Department of Emergency Management.

In August, Tropical Storm Iselle pummeled the Hawaiian Islands with high winds and heavy rain, forcing hundreds of people to seek shelter and knocking out power to over 20,000 residents.

A second storm tracking right behind, Julio, passed hundreds of miles north of Hawaii despite fears that it could wreak havoc on the island chain.

Hurricane Iniki lashed the island of Kauai in September 1992, bringing winds of more than 140 miles per hour (225 kph), killing six people and causing estimated damages of $2.4 billion.

Before that, the last recorded hurricane to hit Hawaii was the Kohala Cyclone in 1871.