Heavy thunderstorms also are in the forecast, prompting warnings from the weather service and O'ahu Civil Defense.

While today was forecast to be mostly sunny, with isolated showers and light southeast winds, the wind was expected to begin blowing tomorrow night at 15 to 20 mph.

By New Year's Eve, high elevations and areas at the base of the Ko'olaus on O'ahu could feel the brunt of the storm and the 60 mph gusts, Matsuda said.

"And the Ko'olaus on the windward side are quite steep," he said. "When the wind gets accelerated downslope, it really gets accelerated."

Leeward locations, including Honolulu, probably will not be hit with such strong gusts, he said.

Matsuda said the heavy rain could prompt flood watches and warnings later in the week.

"Any time you have low pressure, it is quite unstable and very moist," he said.

Matsuda said that there is a chance that the winds and rain will not be as severe as forecast, but he said residents need to prepare for bad weather anyway.

Matsuda said the strong winds could rival those that struck the Islands in January, when winds raked O'ahu with gusts that measured 85 and 60 mph on National Weather Service recording devices.

Those winds snapped 19 utility poles along Kamehameha Highway just outside Wahiawa. Nearly 70,000 electricity customers on O'ahu lost power.