After watching Hawaii island take the brunt of the last major tropical storm, Oahu is looking just a bit more vulnerable under the current projected track of Tropical Storm Ana.

All of the main islands are under threat of Ana’s flash flooding, strong and damaging winds, and coastal inundation and waves Friday through Monday, Central Pacific Hurricane Center metrologists said Wednesday.

But this time Oahu may not escape the worst of the storm’s fury like it did when Tropical Storm Iselle slammed into Hawaii island Aug. 8 and lost its punch.

While the forecast is subject to change, Ana’s center, as of Wednesday, is expected to miss the Big Island to the south late Friday and travel up the island chain, moving along Oahu’s southwest coast Sunday before passing just west of Kauai on Monday.

Officials said modeling data point to the storm reaching Category 1 hurricane status, with sustained winds greater than 74 mph, before it reaches the Hawaiian Islands and then maintaining its hurricane strength throughout its island passage, spreading its wet and windy payload for 50 miles all around.

What can Oahu expect?

Officials said look to Hawaii island and Iselle for a possible preview: The powerful tropical storm caused millions of dollars in damage, ripping off roofs, knocking down hundreds of trees and causing flooding and coastal evacuations as well as prolonged disruptions in power.

The tree that caused so much of the problems in Puna — the albizia — is found all over Oahu, especially the interior, making vulnerable scores of roads, houses, power lines and more.

As a Category 1 hurricane, Ana is expected to be more powerful than Iselle. And because Oahu’s population and infrastructure is much larger than that of Hawaii island, damage could dwarf Iselle’s devastation, officials said.

"It wasn’t that long ago that Puna was still dealing with issues relating to the landfall of Iselle. So we need to prepare for at least that level of impact anywhere across the state as we go through the weekend," said Chris Brenchley, National Weather Service meteorologist.

Brenchley offered a couple of other points that could make Ana more dangerous:

» The storm has been traveling at about 9 mph, which is slower than Iselle, which traveled at an average speed of 14 mph. Forecasters expect Ana to crawl up the island chain over a lengthy 21⁄2 days, which means there’s a greater likelihood of more heavy rain and torrential flooding.

» With a projected path to the south of the islands, the storm will send off its strongest wind and heaviest rain in the direction of the islands. The right front quadrant is always considered the strongest section of a tropical cyclone.

Brenchley said there’s a fear that many people on Oahu, having survived Iselle with ease, will underestimate the power of Ana.

"It’s a dangerous enough situation that folks everywhere need to pay attention for latest updates," he said. "The time to prepare is now."

Dennis Hwang, a University of Hawaii coastal hazard mitigation specialist, said it’s likely many residents will not be prepared.

"People on Oahu haven’t really thought about this that much," said Hwang, who was installing wooden panels on the windows of his Waikele home on Wednesday. "A lot of people don’t think it can happen here."

Hwang, co-author of "Homeowner’s Handbook to Prepare for Natural Hazards," said everyone should have emergency supplies and an evacuation plan at the ready. People should stay tuned to radio and television news, and monitor websites, for the latest information, and be ready to go to a shelter if they live in a low-lying area prone to flooding.

Hwang said a Category 1 hurricane shouldn’t cause any real damage to sturdy buildings. But there is real danger to poorly constructed older homes and those with corrugated-metal roofs. Many older homes were built, for example, without hurricane clips, he said, and those could be in trouble, too.

Such a hurricane could also damage many other species of trees beyond the shallow-rooted and weak-limbed albizia. Palm fronds, for example, could be ripped from their crowns, he said.

An updated version of Hwang’s book is free and online at the University of Hawaii Sea Grant website.

Shelly Kunishige, spokeswoman for the state Emergency Management Agency, said state and county officials are busy preparing for the storm and people should be doing the same.

"Look at what those folks in Puna had to endure," she said. "Can you and your family endure that for a sustained amount of time?"

Brenchley said there is still a lot of uncertainty regarding the path of the storm. But forecasters will be getting some help soon. Data from NOAA’s Gulfstream IV aircraft were scheduled to be added to the National Weather Service forecasting analysis late Wednesday. The plane will sample the environment around Ana. And an Air Force hurricane hunter aircraft will join the team on Friday.

Among those in the community who are preparing to respond to Ana are members of the State of Hawaii Voluntary Organizations Active in Disaster, or VOAD, which includes 26 nonprofit organizations, including the Salvation Army, the Hawaii Pacific Baptist Convention, Hawaii Foodbank, Hawaiian Humane Society, Aloha United Way and Catholic Charities.

The group met Wednesday and discussed preparations for the storm.

"We haven’t been fully tested in some time but we’ll be ready," said Darrell McCain, VOAD chairman.

The Salvation Army has mobile canteens capable of serving hot meals and distributing basic supplies, said Capt. Shane Halverson, emergency disaster services coordinator for the Salvation Army — Hawaiian & Pacific Islands Division.