Even though Ana is expected to weaken as it passes the islands, public officials are still warning about the potential impacts of a powerful tropical storm.

National Weather Service meteorologists said Thursday that Tropical Storm Ana remains a threat for flash flooding, strong wind, coastal inundation and large, pounding surf across the island chain.

As of Thursday night the projected track of the storm continued to run parallel to the islands but was adjusted to follow a course well south and west of Hawaii.

However, West Oahu, Kauai and Niihau remained in the cyclone’s "cone of uncertainty" and thus could still potentially take a direct hit, forecasters said.

What’s more, they said, the storm is hundred of miles wide and is still likely to direct tropical storm-force winds and heavy rainfall toward the islands that could cause life-threatening flash floods and mudslides.

Heavy rainfall was expected to reach Hawaii island Friday afternoon and continue up the island chain through the weekend, reaching Oahu late Saturday.

After anticipating an upgrade to hurricane status for several days, forecasters predicted Thursday that Ana would finally gain Category 1 hurricane strength but only briefly Friday night as the storm passes south of Hawaii island.

After that the tropical storm could lose as much as 20 mph of its wind power as it travels up the islands, said Chris Brenchley, meteorologist with the Central Pacific Hurricane Center.

"It’s not as crazy as it was a few days ago," Brenchley said of Ana.

But it could all change, he said, if new conditions cause the storm to intensify or move in a path toward the islands.

Even if it doesn’t change, the storm could generate sustained wind of 30 mph and gusts of up to 70 mph in some areas. The most vulnerable locations on southern shores could see storm surge of up to 2 feet. Surf on south- and southeast-facing shores could reach 20 feet or more.

"It is still too soon to say with much certainty which islands will be most likely to experience the worst weather," forecasters said. "Everyone should be prepared for the possibility of direct impacts from Ana."

Brenchley urged people to continue monitoring news of the storm.

With the uncertainty about Ana’s impacts, Honolulu officials said they would postpone until Friday decisions on whether to issue an emergency declaration, whether to close city parks, how to handle bus operations and what shelters to open.

Mayor Kirk Caldwell said city officials were heartened to hear the storm had drifted farther south than projected. "But it’s a very, very hard storm to predict," he said.

Caldwell explained that officials didn’t want to create undue "hurricane fatigue" until they get a better picture of how the storm will affect Oahu.

Caldwell said he called an emergency Cabinet meeting Thursday to review responsibilities in anticipation of the storm.

"We take this tropical storm very seriously," he said.

Director of Emergency Management Peter Hirai said the city would open its emergency operations center at 8 a.m. Friday to monitor the storm and coordinate city services over the weekend.

Hirai urged residents to remain flexible and make no firm plans for the weekend.

"We don’t want people outdoors during the storm," he said, "and we don’t want people traveling."

Ross Sasamura, city director of facility maintenance, said his crews have been busy checking and clearing key drainage areas as well as checking generators to make sure they are operational.

He said he helped put together a coordinated utility response team to respond to power failures faster. In addition, he is working with the state Department of Transportation to prepare for responding to potential road emergencies.

Honolulu Ocean Safety Chief Jim Howe said he expects ugly conditions, lots of marine debris and plenty of muddy stream runoff leading to a brown-water advisory over the weekend.

"It could be hazardous to your health," he said. "We’re asking everybody to please use your best judgment before going into the ocean."

Ernest Lau, Board of Water Supply manager and chief engineer, suggested that people forgo the crowds buying water at the stores and fill up empty containers with tap water. He said customers can get 1,000 gallons of water for less than $5.

"All you need is a clean container," Lau said. "Please be prepared,"

City officials also said they were going to revoke all park camping permits for Friday, Saturday and Sunday. There are 87 permits issued.

STORM EFFECTS

The possibility of inclement weather has prompted the following closures, postponements, cancellations and changes in venue. 

HAWAII ISLAND

>> Public schools will be closed Friday. For information on charter school closures, visit www.chartercommission.hawaii.gov. 

>>Hawaii Volcanoes National Park will be closed Friday.

>> All state forest managed lands are closed until further notice, including forest reserves, wildlife sanctuaries, natural area reserves, Na Ala Hele hiking trails and game management areas.

>> All state parks will be closed Friday, until further notice. 

>> State small boat harbors will be closed at 4:30 p.m. Friday, until further notice.

>>Hawaii island public libraries will be closed Friday. Statewide, programs scheduled at all libraries for Saturday are canceled. For more information, visit www.librarieshawaii.org or call your local library.

>> Several state-organized hunts are canceled. For more information, call 974-4221.

OAHU

>> All state parks will be closed Saturday, until further notice. There will be no Friday night camping in park campgrounds. All state forest areas, hiking trails and public hunting areas will be closed Saturday until further notice.

>> Small boat harbors will be closed Saturday, until further notice. 

>> "Heroes of Aloha" will be held 4:30 p.m. to 8 p.m. Saturday at the Neal Blaisdell Center Arena instead of the Waikiki Shell. For more information, visit www.Heroesofaloha.com or call 926-8274.

KAUAI

>> All state-managed forest reserves, natural area reserves, trails, hunting areas and campgrounds will be closed Friday, until further notice.

>> Small boat harbors will be closed Saturday, until further notice.

>> All state parks are closed Saturday until further notice. "Trail closed" signs will be posted at the Kalalau trail head, and campers at Kalalau Beach were warned to evacuate or shelter in place.

MAUI COUNTY

>> Haleakala National Park’s summit and Kipahulu districts will to close at noon Friday. For more information, visit www.nps.gov/hale.

>> All state forest managed lands on Maui, Molokai and Lanai are closed until further notice.

>> All state parks on Maui and Molokai will be closed Friday, until further notice.

>> State small boat harbors on Maui will be closed at 4:30 p.m. Friday, until further notice.

>> All Maui County parks and recreational facilities will be closed beginning Saturday. County campgrounds will be closed beginning Friday.