HONOLULU (Reuters) - Hawaii was spared a direct hit by a major hurricane as Lane, once a monster tempest, rapidly weakened into a tropical storm, even as it unleashed severe flooding on the Big Island and threatened to drench Oahu and Maui.

Lane, with maximum sustained winds diminishing to near 70 mph (110 kph), was forecast to slowly make its nearest approach to land just west of the U.S. Pacific island chain over the weekend, bringing tropical storm conditions to Maui and the state’s most populous island, Oahu, late on Friday.

More than two feet (60 cm) of rain had fallen in a 36-hour period by Friday night on the windward side of the island of Hawaii, popularly known as the Big Island, where the Weather Service reported “catastrophic flooding.” More than 40 inches of rain was recorded in Piihonua and Waiakea on the island late on Friday, the weather service said.

Flash flooding and mudslides on the Big Island forced road closures and evacuations as police and emergency crews conducted numerous rescues of people stranded in vehicles and homes by high water on Friday.

“Roads all over are impassable due to extreme flooding,” said Hawaii resident Lili Koi on Twitter late on Friday night. “That means ambulances and even police are not able to get through. Say some prayers and be safe.”

A number of structures on the island of Hawaii were destroyed, said Melissa Dye, a Weather Service spokeswoman in Honolulu.

She said two Hilo-area neighborhoods were evacuated. But no injuries were reported.

“I’ve never seen this, so much devastation of the river flowing down off of Komohana (River),” said long-time resident Tracy Pacheco in Hilo. “I just came from Pahale Park, and there’s no park.”

FORECASTS LESS DIRE

Official bulletins grew less dire through the day. Into the evening, forecasts made clear that Hawaii had been spared from the threat of its first direct hit by a major hurricane in a quarter of a century.

Lane was downgraded on Friday to a Category 1, the lowest ranking on the five-step Saffir-Simpson scale, as it churned through the Pacific south of Oahu, the National Weather Service said. It was downgraded again to a tropical storm shortly before 5 p.m. as its maximum sustained wind speeds fell below 74 mph.

The storm was nearly stationary south of Hawaii on Friday night. It was expected to move slowly toward the northwest later and then turn west on Saturday and continue over the weekend, the National Weather Service said in an advisory.

Forecasts predicted that Lane, which peaked as a Category 5 hurricane with top sustained winds of 160 mph (260 kph) earlier in the week, to diminish into a tropical depression by early on Sunday.

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The turn of events was welcomed by residents who had spent much of the past few days stocking up on food, water, gasoline and batteries and boarding up their windows.

TORRENTIAL DOWNPOURS, EVACUATIONS

Still, the storm posed a considerable weather hazard to large parts of the state, with the island of Hawaii bearing the brunt of torrential downpours from Lane.

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On Oahu, where 70 percent of Hawaii’s 1.4 million residents live, Honolulu Mayor Kirk Caldwell told the Weather Channel that the city has moved its emergency-response equipment to higher ground for the time being.

He said Honolulu, the state’s capital and largest city, is vulnerable to floods and slides because it is partly ringed by mountains.

“We have asked our residents in these areas where they know it floods to be ready to leave,” Caldwell said, adding that 1,100 people were staying in emergency shelters throughout the city.

New Yorker Rigo Pagoada, 43, who was on vacation on Oahu with his family, said he felt lucky it had been largely spared.

“We’ve been very fortunate,” he said. “It’s sad to see the (impact on) the Big Island.”

Hawaii’s major airports remained open during the storm, though 22 flights were canceled at Honolulu’s main airport, according to online tracking service FlightAware.com. Several airlines also canceled services to Kahului Airport on Maui in anticipation of severe weather, the state transportation department said.

The governor said travelers should expect congestion at the airports on Saturday and Sunday from the backlog of canceled flights.