HONOLULU (AP) — As emergency shelters opened, rain began to pour and cellphone alerts went out — and the approaching hurricane started to feel real for Hawaii residents.

Hurricane Lane was forecast to continue its northwest turn into the islands Thursday, which would make it the most powerful storm to hit Hawaii since Hurricane Iniki in 1992.

“Everyone is starting to buckle down at this point,” said Christyl Nagao of Kauai. “Our families are here. We have businesses and this and that. You just have to man your fort and hold on tight.”

Officials opened shelters on the Big Island and on the islands of Maui, Molokai and Lanai on Wednesday. They urged those needing the Molokai shelter to get there soon because of concerns the main highway on the south coast of the island could become impassable.

On the island of Oahu, which was put on a hurricane warning late Wednesday, shelters were scheduled to open Thursday. Officials were also working to help Hawaii’s sizeable homeless population, many of whom live near beaches and streams that could flood.

Hawaii Emergency Management Agency Administrator Tom Travis said there’s not enough shelter space statewide and advised those who not in flood zones to stay home.

Officials warned the limited shelter space should be a “last resort” and that the shelters are not designed to withstand winds greater than about 40 mph.

“Whenever possible, the public should plan to shelter in place or stay with family or friends in homes outside of these hazard areas that were designed, built, or renovated to withstand anticipated conditions,” the city and county of Honolulu said in a statement.

Hurricanes are ranked 1 to 5 according to what is known as the Saffir-Simpson Hurricane Wind Scale. Hurricane Lane is at Category 4, which means winds from 130 to 156 mph.

The Big Island was already starting to see Lane’s first effects, Gov. David Ige said at a news conference Wednesday.

The hurricane’s outer rain bands were bringing showers to some parts of the island, said Matt Foster, a meteorologist with the National Weather Service.

The eastern side of the island picked up nearly 3 inches of rain in three hours, Foster said.

Melanie Davis, who lives in a suburb outside Honolulu, said she was gathering canned food and baby formula.

“We’re getting some bags of rice and of course, some Spam,” she said of the canned lunch meat that’s popular in Hawaii.

She was organizing important documents into a folder — birth and marriage certificates, Social Security cards, insurance paperwork — and making sure her three children, all under 4, have flotation devices such as swimming vests “just in case.”