Though now a tropical storm, former Hurricane Darby could be within striking distance of the Hawaiian Islands as early as tonight.

“It’s still potentially dangerous, especially if it stays on the current track,” National Weather Service meteorologist Chevy Chevalier said.

Darby’s winds were clocking at 63 mph, with gusts of 80 mph Thursday night. At 8 p.m. Darby was 490 miles east of Hilo, moving west at 13 mph.

“We don’t expect weakening if it follows the current track until it’s north of Oahu,” Chevalier said.

As for surf, swells are expected to hit the islands today and Saturday, possibly damaging coastlines. The east shores of Hawaii island and Maui County are under a high-surf warning from 6 a.m. today to 6 a.m. Sunday.

The Big Island, Maui, Molokai, Lanai, Molokai and Kahoolawe were under a tropical storm watch Thursday night, meaning tropical storm conditions could occur within the next 48 hours.

Depending on the track, it could affect Oahu. “It just depends — one little nudge this way or that,” Chevalier said.

Oahu could see Darby pass to the east of the island late Sunday into early Monday morning. If it shifts, Oahu could get storm-strength winds, high surf on east shores and rain.

Depending on a ridge of high pressure, Darby could slow, and create more of a problem with heavy rain and subsequent flooding.

Unlike Celia, the last hurricane to cross into the Central Pacific, “Darby stayed a little farther to the south where warmer waters are,” Chevalier said. “It’s more of a threat now.”

“Last year we had 15 named storms, and not one of them impacted us much, so that was a lot of good luck,” Chevalier said. “This year is quieter,” with cooler La Nina conditions, but “that doesn’t mean we’re not going to see any impacts this year,” he said.

The Weather Service and counties urge residents to be prepared for the hurricane season.

“Just be prepared for flooding. That’s going to be the primary threat for this,” Chevalier said.

Hawaii County Civil Defense warned the public to be ready for the storm with high-surf warnings for east shores, tropical storm force winds, heavy rain and flooding, and mud- and rockslides.

The county canceled all camping reservations at county parks and shut down the Kalapana lava-viewing site, starting today and continuing through Sunday.

All pavilion reservations at county parks are canceled Saturday and Sunday. Swimming pools and the Hoolulu Complex will also be closed on those days.

The following public schools are scheduled to be opened as emergency shelters at 4 p.m.: Hilo High, Waiakea High, Kalanianaole Elementary, Keaau High, Pahoa High, Laupahoehoe Community Charter School, Honokaa High and Intermediate, Kohala High and Elementary, Waikoloa Elementary, Kealakehe High, Konawaena High, Kau High and Mountain View Elementary. Bring bedding, food, water, medications and any needed personal items.

Monitor local radio broadcasts for information updates, and plan early for possible impacts from wind and rain to homes, businesses and communities. For more information go to hawaiicounty.gov/ civil-defense.

Maui County advised residents to assemble their emergency kits and stock up on seven days’ worth of food, water and medicine. They were also encouraged to fuel their vehicles, secure loose objects on their property, and those living in flood inundation areas to have evacuation plans ready.

Sign-up for the Makaala emergency alert system is available online, mauicounty.gov.

Recreational boaters should secure their boats and boating equipment, the Coast Guard said. Small boats may be removed and secured in place safe from high winds, and owners of large boats are urged to move them to protected marinas to prevent them from breaking free of moorings and damage.

Visitors should heed lifeguard and public health and safety officials’ warnings. Riptides and high surf can also affect beaches well ahead of the storm. Swimmers should stay clear of beaches until official say it’s safe. Runoff can contaminate nearshore waters for several days after a storm.