Board of Water Supply worker Daniel China inspects a boulder that rolled down a steep hillside on Malu Place, took out a fire hydrant and came to rest in a garden about 20 feet from a home, right rear. No one was injured. Richard Ambo • The Honolulu Advertiser

A cold front brought strong northeasterly winds and dumped as much as six inches of rain overnight in parts of O'ahu, passed over Maui this morning and was due to hit the Big Island this afternoon. Yesterday, the storm caused landslides and flooded roadways on Kaua'i.

O'ahu received a thorough drenching overnight and Kevin Kugiyama suspects the wetness is to blame for sending a 3-by-4-foot boulder tumbling down the ridge near Wilhelmina Rise and narrowly missing his home off Kilauea Avenue.

Kugiyama, 30, had just awakened at 7:45 a.m. when a rumbling began echoing through the house at 5373 Malu Place, the windows all shut tight against the rain.

"My window overlooks the mountain," said Kugiyama, who works as a courier for a clinical laboratory company. "I heard a thundering noise, and when I looked up the rock was coming down the mountain already... it sounded like a horse galloping, but louder."

It was headed straight for the house, too, and Kugiyama instantly grabbed the phone and dialed 911. Luckily, the rock took a sudden turn and missed the house, going airborne over a family car parked on the street and hitting the curb opposite the house.

The rock then took out a fire hydrant and bounced back across to Kugiyama's side of the street, hitting the garden wall at his next-door neighbor's house (where, he said, nobody was home) before it came to rest in the landscaping. Fire crews arrived about 15 minutes later to turn off the water to the fountaining hydrant, he said.

Around O'ahu, the fallout was limited to fender-benders, flying signs and minor flooding in low-lying areas. Hans Rosendal, National Weather Service lead forecaster, said an urban and small-stream flood advisory was in effect this morning for Windward O'ahu, Lana'i, Moloka'i and north and east Maui.

Winds, which gusted to 50 mph overnight in some areas, were being reported in the 30-40 mph range in others, he said. Wind conditions varied drastically from place to place because they were blowing only a few hundred feet above the ground, Rosendal added.

"There are some obstacles that hit that stream of wind, and it will mix down to the surface," he said. "You might be in one area and think there's no wind, then you move a few hundred yards in a different direction and it blows pretty hard."

The statewide forecast is for the winds and rain to abate tonight and for sunnier, warmer weather tomorrow. Lows tonight are predicted to be in the low- to mid-60s and for highs tomorrow to approach 80.

Wailuku and Kahului were drenched by more than five inches of rain over a six-hour period ending at 8 a.m. Hana and Lana'i recorded almost four inches or rain during the same period, but Moloka'i saw less than a half-inch.

'?ao Intermediate School in Wailuku was closed and some streets were flooded, but Maui civil defense officials reported no major damage or road closures.

Kamehameha Highway, near Waikane, was awash in up to three feet of water early today, causing traffic delays to morning commuters as the Ko'olau communities took the brunt of the downpour.