Heavy rain lashed Windward O'ahu and parts of the North Shore much of yesterday, causing minor flooding of roads and at two homes.

The National Weather Service issued a flash-flood warning twice yesterday as heavy rain fell from Waialua, Mokule'ia and Hale'iwa down the coast to Kane'ohe. As the rain let up, the warning was down-graded to an urban and small stream flood advisory at 8 p.m.

The weather service is forecasting scattered showers this morning with isolated thunderstorms this afternoon. Tonight should be mostly cloudy with scattered showers, the weather service said.

Throughout the afternoon, O'ahu Civil Defense volunteers monitored runoff from Waiahole and Waikane streams in Windward O'ahu. The rising flood waters finally forced police to close Kamehameha Highway between Waiahole Homestead Road and Haupoa Street at about 6:40 p.m. The highway was reopened at about 7:50 p.m.

Hau'ula Homestead resident Kathryn Heath said it was raining "buckets" late yesterday afternoon as she drove home through Kahalu'u at about 3:15 p.m. At that time, she feared that the highway would soon become impassable.

"It's bucketing out here and all the streams are running," Heath said a half-hour before Kamehameha Highway was closed.

Heath lives on high ground and said her home likely will be spared by the flood waters. She also said she welcomed the rain.

"I'm just going to stay home. I'm not going to go look for any problems," she said. "It's raining nice and heavy, but it's actually kind of pleasant."

The Fire Department yesterday responded to flooding at a home on He'eia Street in the afternoon and minor flooding was reported in Halawa Valley earlier in the day.

The National Weather Service reported that a funnel cloud was seen over Mililani at about 4:45 p.m.

A 45-year-old man was critically injured when he was struck by a car as he attempted to cross Kamehameha Highway near Kualoa Ranch. Emergency Medical Services personnel said it was raining heavily at the time and visibility was poor.

The man was taken by ambulance to The Queen's Medical Center. Plans to use the Army medevac helicopter to transport the injured man were called off because of the bad weather.

City officials last night said there were two sewage spills in Kane'ohe caused by the heavy runoff that entered the sewage system.

The larger spill was reported at 5:30 p.m. at the Kane'ohe wastewater pretreatment facility on Kulauli Street, where about 50,000 gallons of sewage spilled before crews could contain it at 6:05 p.m.

The city said some of the sewage spilled into Kane'ohe Stream, which flows into Kane'ohe Bay.

Meanwhile, an estimated 22,500 gallons of untreated sewage spilled from a manhole at the Punawai pump station across from King Intermediate School. The spill began at 5:15 and was brought under control at 6:45 p.m.

The rain also may have been responsible for a mudslide near Kalaheo High School in Kailua yesterday.

The high school football game between Kailua and Kahuku was postponed until today because of bad weather at Kahuku High.

Two planes leaving Honolulu International Airport were struck by lightning within an hour of each other yesterday, Transportation Department spokesman Scott Ishikawa said.

Hawaiian Airlines Flight 20 from Honolulu to Sacramento was hit by lightning about five to 10 minutes after its 1:30 p.m. departure. The Boeing 767, with 274 passengers and crew aboard, returned to Honolulu as a precaution.

About an hour later, Aloha Airlines Flight 270 heading for Kona was struck shortly after its departure from Honolulu. That plane, a Boeing 737 with 199 passengers and crew, also returned to the airport and the passengers were put on another flight, Ishikawa said.

There were no injuries on either plane, he said.

Airport officials reported stormy weather over the Kaiwi Channel at the time of the lightening strikes, but there were no reports of any flights being canceled because of the weather, Ishikawa said.

Earlier, thunder and lightning were reported over the Pali Highway yesterday as a week of blue skies were replaced by rain and a pattern of unstable air likely to hang around O'ahu all weekend.

There were no reports of damage but police reported that a tree in Kailua was struck by lightning about 11:30 a.m., said Ray Tanabe, a weather service forecaster.

The weather service did not have any rainfall totals for much of the affected areas because of mechanical problems.

The morning rain was so heavy over the Ko'olau mountains at 11 a.m. that the weather service at first issued an urban and small stream flood advisory for Hau'ula, Ka'a'awa, Kahalu'u, Kane'ohe, Waikane, Maunawili and Waihe'e. The advisory was extended through the afternoon as the soaking clouds drifted northward over Hale'iwa, Waialua, Mililani, Kunia and parts of Wai'anae.

An upper trough dropping in from the northeast continued to push Tropical Storm Jova away from the state but in the process also destabilized the atmosphere, bringing the rain, Tanabe said. Meanwhile, Tropical Storm Kenneth, is "lurking" well southeast of the state, but is forecast to cross into the Central Pacific sometime Tuesday, the weather service said.

Effects of Kenneth, if any, on the main Hawaiian islands are still more than a week away, it said.

Reach Mike Gordon at mgordon@honoluluadvertiser.com and Curtis Lum at culum@honoluluadvertiser.com.