Winds die down but rain is still a threat to Hawaii as Lane downgraded to tropical storm

Strong winds have died down but officials warned that torrential rains still remained a big threat to Hawaii after once-powerful Hurricane Lane was downgraded to a tropical storm.

Forecasters said as much as 25 centimetres of rain could fall on Oahu and Maui as the storm churned about 177 kilometres south of Honolulu, moving north at 5kmh.

"Don't let your guard down," Brock Long, administrator of the Federal Emergency Management Agency, said during a telephone briefing in Washington. "Tropical storms can be very dangerous and Hawaii is not in the clear."

The storm has dumped nearly four feet of rain in some areas of the Big Island. Maui has seen about 30cm of rain and wind gusts up to 80kmh in the past 24 hours. Both islands have reported flooding and landslides.

Long said the biggest impact has been on transportation due to debris in roadways, downed power lines and damage to infrastructure, mostly on the Big Island. No storm-related deaths have been reported.

On Saturday, winds on Maui were blowing about 18kmh and the storm was expected to turn west, which would lessen the threat to the islands.

The American Red Cross said more than 1100 people were staying in shelters, mostly in Oahu. And while the number was down from earlier reports, officials said the figure shows a lot of people are still displaced.

Lane first approached the islands earlier this week as a Category 5 hurricane, meaning it was likely to cause catastrophic damage with winds of 252kmh or above.

But upper-level winds known as shear swiftly tore the storm apart. By Saturday, the National Weather Service said Lane had maximum sustained winds of 97kmh.

The outer bands of the hurricane dumped as much as 114 centimetres of rain on the mostly rural Big Island, the Weather Service said. The main town of Hilo, with 43,000 people, was flooded Friday with waist-high water.

Windswept flames and smoke rush toward a pair of luxury homes in Launiupoko, Hawaii, on Friday. The fire was whipped up by the approaching tropical storm Lane. Photo / AP

As flooding hit the Big Island, winds fanned brush fires that had broken out in dry areas of Maui and Oahu. Some residents in a shelter on Maui had to flee flames, and another fire forced people from their homes.

Josh Galinato said he was trying to sleep when he smelled smoke in his apartment in the tourist town of Lahaina.

"I opened up my front door, and I just saw the fire spreading and coming downhill," Galinato said. He and neighbours honked horns to alert others.

In Waikiki, the man-made Ala Wai Canal was likely to flood if predicted rains arrive, said Ray Alexander of the US Army Corps of Engineers. The canal marks the northern boundary of the Waikiki tourist district.

"The canal has flooded in the past, and I believe it's safe to say based on the forecast of rainfall it's likely to flood again — the impacts of which we aren't prepared to say at this time," Alexander said.

Major flooding could damage 3000 structures and cost more than US$1 billion in repairs, the Honolulu Star-Advertiser newspaper reported, citing Corps estimates.

Not everyone feared the storm on Saturday.

At sunrise, surfers paddled out at Honolulu's Ala Moana Beach Park amid waves that appeared smaller than Friday's swells. Joggers ran around the park as a light rain fell with a bit of a breeze. Occasional stronger rain showers moved through the area, soaking the streets and early-rising tourists.

The central Pacific gets fewer hurricanes than other regions, with only about four or five named storms a year. Hawaii rarely gets hit. The last major storm to hit was Iniki in 1992. Others have come close in recent years.

- AP