Updated at 7:15 p.m. ET
Hurricane Lane has been downgraded to a Category 3 storm as it slowly makes its way toward the island chain.
As of 2 p.m. local time, Lane was centered about 260 miles south of Honolulu, Melissa Dye, a meteorologist with the Central Pacific Hurricane Center, told NPR.
Even so, its outer bands continue to cause significant damage on the island of Hawaii, forcing residents to stay put.
Mudslides, landslides and flash flooding are causing road closures throughout the Big Island, Dye said.
The Hawaii County Civil Defense Agency is advising residents not to venture out onto roads, and announced several bus lines have been canceled as of Thursday. The agency does not expect services to resume until Saturday, at the earliest.
The center of Lane is moving northwest at 6 mph with maximum sustained winds of 125 mph. It was expected to turn toward the west Saturday and Sunday, and pick up speed, National Weather Service said.
Even if Lane's center skirts past land, the storm could have a devastating effect on the islands, said Steve Goldstein of the National Weather Service.
"You do not need a direct strike to have major impacts from a hurricane this strong," he told reporters. It is possible some areas may be hit with up to 30 inches of rain, and face likely flooding.
The National Weather Services warns: "Hurricane Lane will also bring other life threatening conditions with damaging winds, dangerous surf, coastal storm surge and intense flooding rains through Saturday."
Oahu island, which includes the capital Honolulu and most of the state's population, is under a hurricane warning, along with Maui County and Hawaii County. A hurricane watch is in effect for Kauai County.
Lane is expected to remain a hurricane "as it approaches the islands," according to the agency. Hurricane-force winds will extend up to 40 miles out from the storm's center; tropical-storm-force winds will extend up to 140 miles.
"We still are expecting wind, rain, flooding effects that would affect statewide. We want to assure you that federal state and county emergency responders are working in coordination to keep the community safe," Hawaii Gov. David Ige said Wednesday.
State officials opened shelters on Wednesday with more opening on Thursday, The Associated Press reported.
Hawaii has had warnings about hurricanes before, though the last storm with significant damage was Hurricane Iniki in 1992. Officials are concerned that people have been complacent about preparations.
Davelle Finau of Oahu says she's not too concerned about the storm.
"Filling up [the] tank and stuff. Where you going to go with a full tank of gas? It's a small island. You're just going to go up the mountain and come right back down," Finau told NPR's Adrian Florido.
Even so, many residents are following recommendations to stock two weeks' worth of supplies. Grocery stores have been packed, and some gas stations have had long lines, Adrian says.
The governor's office said Wednesday that a presidential disaster declaration was approved for the state, which enables the Department of Homeland Security and the Federal Emergency Management Agency (FEMA) to take certain actions.
Park closures in much of the state go into effect Thursday. Public schools and some highways will be closed as well.
The governor said commercial harbors would also close and ordered boats to leave before the storm. "This is because the harbors are our lifeline to essential food and products," he said on Twitter.
Authorities warned residents on the coasts to be especially cautious — the weather service said large waves and a storm surge would mean water levels 2 feet to 4 feet above normal tide levels in certain shores facing south and west.
The weather service said some shorelines are likely to face "significant coastal erosion" because of "very large and damaging surf."
FEMA warned residents on shores to secure their boats and watch for salt damage to windows and doors, among other tips.