Hawaii faces heavy rain, strong winds as Lala weakens to tropical storm

Storm skirts Big Island without making landfall, rainfall could produce flooding, mudslides

Hurricane Lala weakened to a tropical storm Sunday after skirting Hawaii without making landfall, but it wasn't done punishing the Big Island with hurricane-force gusts.

Total rainfall of nearly one metre was expected on the higher windward slopes, turning rivers into raging torrents and threatening mudslides.

Tropical storm conditions were spreading westward from Maui to Oahu and then Kauai, and the National Hurricane Center warned that wind speeds atop mountains and on the windward and leeward slopes are often up to 30 per cent stronger than the near-surface winds used to categorize storms.

Powerful waves pounded the Big Island's coast as Lala slowly passed by. Howling winds whipped palm trees and waterways swelled with fast-moving run-off from relentless rain that blew nearly sideways.

More than 130,000 households were without power Sunday morning across Hawaii's three largest islands, according to the utility tracker poweroutage.us. At least three hospitals were operating on generator power, Gov. Josh Green said.

At least one person died in a car accident in the South Point area of the Big Island, while 19 roofs were lost in the "enormous storm," the governor said Saturday evening.

"There have been a lot of roads impacted, our crews have already been out to more than 30 sites."

A search-and-rescue mission including Civil Defense, the National Guard and Coast Guard was launched after flash floods apparently swept several occupied homes off their foundations in the coastal communities of Na'alehu and Wai'ohinu, near the island's southern tip, Hawaii County Mayor Kimo Alameda said early Sunday.

"What makes this very challenging is that there's rushing water, there's debris, and there's boulders on the road and it's dark," Alameda said.

Tropical storm warnings in effect

Tropical storm warnings were in effect for the islands of Maui, Molokai, Lanai, Kahoolawe, Oahu, Kauai and Niihau as the storm moves west, raising the possibility of destructive flooding and even wildfires kicked up by strong winds.

As of 2 a.m. Sunday in Hawaii, Lala was centred about 170 kilometres west-northwest of Kailua-Kona and about 160 kilometres south of Honolulu, with tropical storm-force winds extending as much as 280 kilometres from its centre.

Lala was sustaining top winds of 110 km/h and moving northwest at about 24 km/h. Forecasters expect it to regain hurricane strength midweek once it's well west of the island chain.

By the time Lala's completely gone, some higher-altitude places on the Big Island, dominated by the towering Mauna Kea volcano, will have been hit with as much as 89 centimetres of rain, forecasters said, enough to loosen steep slopes where some of the 210,000 islanders live off the grid in improvised housing.

'Hunker down, cross my fingers'

On Saturday, shelters were opened, events were cancelled and ranchers were urged to leave their cattle in pastures, rather than structures that might collapse.

Bobby Camara, a 75-year-old lifelong resident, said he planned to "hunker down, cross my fingers, hope the lights don't go out" at a care home just outside Hilo. He said gas stations were busy as people sought fuel for chain saws and vehicles.

"I think stocking up is part of life over here. ... You learn to be self-reliant."

Mike Caputo, who lives in Keaau, near the Big Island's east coast, said his power generator was ready and a 37.8-kilolitre home water tank was full.

He said the main concern was flash flooding and fallen trees, especially albizia, a common tree.

"They're not very sturdy, but they grow extremely large," said Caputo, 50, a local fire captain. "They can make roads impassable."

Christine Matsuda, who lives in Waimea on the northern side of the island, said "big gusts every few minutes rattle the whole house."

"We're finding unexpected leaks in places that don't see water under normal conditions."

Lala had intensified from a tropical storm into a hurricane early Saturday as its maximum sustained winds increased to 120 km/h, the hurricane centre reported, making it a Category 1 hurricane. The Big Island is Hawaii's largest and has a population of about 210,000.

A hurricane last made landfall on the islands in 1992, when Iniki — a Category 4 storm — lashed Kauai.

"It did $3 billion worth of damage. It destroyed thousands of homes, and it did kill six people," said Green. "We just can never know if a storm is going to turn."

Lala strengthens into hurricane as it barrels toward Hawaii

The Big Island was last hit directly in 1871, when a Category 3 hurricane hit the northeast corner, according to research by a University of Hawaii atmospheric scientist.

The hurricane centre predicted 20.3 to 30.5 centimetres of total rainfall across Maui and the lower elevations of the Big Island, and 10.2 to 15.2 centimetres across the island chain.

Many Hawaii residents are still dealing with the aftermath of devastating floods in March.