The recent winter storm dumped more than rain — the snow-capped summit of Mauna Kea, as seen from upper Kaumana, offered Big Island residents a December delight. It is the first snow of the season. Kevin Dayton • The Honolulu Advertiser

Heavy rains also loosened and dumped boulders and trees onto Diamond Head Road. . Richard Ambo • The Honolulu Advertiser

Three to four inches of snow fell on the summit region yesterday, said Ron Koehler, general manager for Mauna Kea Observatories Support Services, the agency that oversees the area. Drifting snow was nearly a foot deep in some places.

"It’s very pretty," he said. "It’s more than we normally get in early December."

Roads to the summit were closed at 4 p.m. yesterday and remained closed today as snow plows cleared them today, he said.

On O'ahu, the rain caused two rockslides on Kalaniana'ole Highway on the Windward side last night. A third rock of unknown size had to be removed last night from Kamehameha Highway near Waimea Bay.

Debris on Diamond Head Road also drew city cleanup crews, but a boulder nearly the size of a Mini Cooper fell off the state-owned crater sometime last night and remained on the shoulder not far from the Diamond Head lookout.

"The debris has been cleared up but the boulder is still there," said Larry Leopardi, director of the city’s Department of Road Maintenance. "It is pretty big."

According to Department of Transportation spokesman Scott Ishikawa, at about 7:30 p.m. eight boulders fell onto Kalaniana'ole Highway about 1,500 feet west of Sea Life Park. The biggest boulder measured 3 feet by 2 feet with the rest the size of coconuts and footballs, Ishikawa said.

The highway was shut down in both directions for almost two hours before being reopened at 9:10 p.m., Ishikawa said. It was later closed again but reopened at 11:30 p.m.

No boulders fell in the area protected by the netting put up by the state at Makapu'u this summer, Ishikawa said.

State engineers went to inspect the Sea Life Park area today, Ishikawa said. The area, and others like it, may have to be cleared of loose rocks, Ishikawa said.

Fire Capt. Kenison Tejada said at about 7:30 p.m. a woman in her 20s driving a Volkswagen Passat hit one of the boulders.

The airbag in the woman's car deployed and she wasn't hurt.

The second slide happened about 9:45 p.m. between the Koko Head rifle range and Sandy Beach, Ishikawa said.

Engineers were to be on the scene this morning.

Drier conditions are forecast for O'ahu today, but there is a chance of heavy rains on Maui, Moloka'i and the Big Island as the storm system, which first hit Saturday, works its way down the island chain.

Firefighters responded to a handful of flooding calls at homes and businesses as parts of O'ahu got as much as 2.8 inches of rain in a 12-hour period ending at 5 p.m., the National Weather Service said.

Lightning strikes were reported in Windward O'ahu, the first about noon in Enchanted Lake in Kailua, the second almost an hour later in Ha'iku Plantation in Kane'ohe.

Tejada said lightning blew a 2-foot hole in the roof of a house on Hulupala Place in Kane'ohe. No one was hurt.

Corey Downs, a 24-year-old Kailua resident, said he was sitting in his house on Akumu Street when he looked out the window and saw a bolt of lightning strike a light pole. Tim McLemore, a 39-year-old Palolo resident, said he was driving down Pali Highway, looking out toward Kailua, when he saw lightning knife straight down into Enchanted Lake. "I thought I’d see a crater or something," McLemore said. "It’s fortunate it’s just the power (that was affected)."

Officials closed pools at five county parks — 'Aiea, Kalihi Valley, Manoa, McCully and Kailua — because of the threat of lightning.

Power failures were reported throughout the day in Wai'anae, Wahiawa, Mililani, Enchanted Lake and various neighborhoods in East Honolulu.

Margaret Penna, a cashier at Ace Hardware Hawaii in Kane'ohe, said she drove through rain-soaked roads on the way to work from Waimanalo, and worked for a few seconds in the dark yesterday when the electricity went out briefly.

Customers, she said, were buying tarps and submersible pumps.

Ishikawa said a portion of the cliff behind the barriers near the Castle Junction interchange collapsed, but did not spill into the street. He said a few rocks fell onto Kamehameha Highway near Kapapa Gulch in Mililani.

On Maui today, steady rain drenched the island overnight, causing a mudslide that covered the remote Pi'ilani Highway near Kanaio. County highways crews were cleaning the mess up this morning.

Flooding continued in coastal areas of Kihei, but county highways chief Brian Hashiro said South Kihei Road wasn’t hit as badly this morning because most of the drainage outlets were cleared.