HILO, Hawaii — Heavy rains hit parts of Hawaii and strong waves pummeled shorelines as a downgraded yet potent Pacific storm passed near the island state.

Though Tropical Storm Madeline was no longer a hurricane, the weather’s uncertainty couldn’t let Hawaii’s Big Island relax.

There were periods of intense rainfall Wednesday as the National Weather Service downgraded Madeline, with winds falling below hurricane strength of 74 mph.

Wind speed diminished steadily throughout the day and by 11 p.m. (2 a.m. PDT Thursday), they were swirling at 50 mph. Forecasters said continued weakening was expected.

Madeline’s center was about 200 miles south of Hilo and moving west-southwest and away from the state at 14 mph. Though the storm was not predicted to make landfall on any Hawaiian island, the Big Island and Maui County remained under tropical storm warnings because of threats from wind and rain.

Strong winds were gusting on Oahu as a series of bright blue flashes lit up the night sky above Honolulu. The power went off in the hillside neighborhood but the lights in most of downtown Honolulu remained on. There was no rain accompanying the blustery weather and only scattered clouds whizzed by overhead.

On the Big Island, waves crashed into a seawall that surrounds Liliuokalani Gardens Park at Hilo Bay. Water accumulated on the grass of the gardens, leaving stairs of a pavilion partially submerged.

“That heavy rainfall is interspersed with sunny patches,” said Kanani Aton, spokeswoman for Hawaii County Civil Defense.

Officials said residents should continue to be prepared for more rain, strong winds and high surf overnight. The rainfall may lead to dangerous flash floods and mudslides, the weather service warned.

“It doesn’t matter if it’s a strong tropical storm or a category 1 hurricane,” said Eric Lau, a meteorologist with the weather service. “If you have 70 mph winds versus 75 mph winds, it’s still a strong storm, so residents still need to be prepared.”