HILO » Despite forecasts that show Tropical Storm Ana bypassing Hawaii island, shelters will open starting at noon Friday.

The National Weather Service said Thursday that Ana might pass about 80 miles southwest of Hawaii island Friday night and Saturday.

The Big Island will also be under a flash-flood watch starting noon Friday until 6 p.m. Sunday. Rainfall amounts could be 6 to 8 inches, with up to 12 inches along the southeastern and western sides of the island.

Designated shelters are at Kau, Keaau, Kohala, Kealakehe, Konawaena, Hilo and Waiakea high schools; Pahoa and Honokaa high and intermediate schools; and Pahala, Kohala and Waikoloa elementary schools.

Maria Lutz, director of emergency services with the American Red Cross, said a search is underway for volunteers in preparation for the storm.

"We’re ramping up and making sure we have teams for each shelter," she said.

Hawaii County Civil Defense Director Darryl Oliveira announced Thursday that the Puna Geothermal Venture power plant will go offline Friday. During Tropical Storm Iselle in August, the plant stayed operational and was forced to shut down after trees fell on transmission lines, releasing steam and causing public concern.

The county also informed residents on the west side of the island to anticipate high surf and surge, even if Ana doesn’t make landfall.

All public and charter schools, along with Kamehameha Schools, St. Joseph School in Hilo, and Waimea Country School and Parker School, will be closed Friday. All Hawaii County parks will be closed Friday until further notice.

Meanwhile, the June 27 lava flow from Kilauea Volcano heading toward Pahoa is widening rather than advancing.

Hawaii County officials and representatives from the Hawaiian Volcano Observatory said Thursday that the flow had stalled, although some expansion could be seen at its front. According to information on the HVO website, the width ranges from 220 to 550 yards.

Oliveira said the most recent aerial assessment showed the flow’s activity had slowed down overall.

"It wasn’t very aggressive; there wasn’t a lot of burning," he said during a daily conference call with the media Thursday.

Lava had advanced only about 50 yards since Monday, but Pele’s work isn’t done yet.

Steve Brantley, Hawaii Volcano Observatory’s acting scientist-in-charge, said the flow remains active as evident from the surface flows behind the front of the flow.

"So lava is still finding its way from Puu Oo," he said.

The front of the flow was about 0.8 mile from Apaa Street near the Pahoa Transfer Station on Thursday.

The HVO has been reporting the flow was 0.6 miles from Apaa Street, and the change reflects the measurement of the flow along the steepest descent line.