TRACKING ANA

A strengthening Tropical Storm Ana remained on track to reach the Big Island as a Category 1 hurricane this weekend, forecasters said Tuesday evening.

The storm is expected to be upgraded to a hurricane this morning and bring sustained winds of up to 75 to 80 mph Saturday as it skirts the south end of the island.

Darryl Oliveira, Hawaii County Civil Defense administrator, said residents could expect to see impacts as early as Friday from the storm, which could produce surf between 25 and 40 feet on the southeast coast and rainfall between 10 and 15 inches.

Oliveira said residents can expect a “substantial amount of rainfall” on the southeast side of the island based on Tuesday’s forecast, but he noted heavy winds and rain also could impact everyone else.

“If it passes the southern tip of the Big Island, it still could have tropical storm-force winds as far north as Puna and Hilo areas,” he said.

National Weather Service forecaster Tom Birchard also cautioned that all isle residents should be prepared.

“At this point, we’re all potentially impacted,” Birchard said.

Residents should be reviewing their emergency plans and stocking disaster kits, he said.

Flooding could be an issue in Ka‘u since its soil already is saturated by recent rains, Oliveira noted.

As of 5 p.m. Tuesday, the storm was 760 miles east-southeast of Hilo and 775 miles east-southeast of South Point.

While NWS meteorologists were confident Tuesday the storm would reach hurricane strength, where it will be this weekend remains less clear.

“The cone of uncertainty could take it well to the north and south of the Big Island,” said Tom Evans, meteorologist.

Where it goes might depend on a trough of low pressure to the north of the system, he said.

Warm water in the range of 81 to 82 degrees along the forecasted track plus light wind shear are providing favorable conditions for Ana to continue strengthening. The water is about 3 degrees warmer than normal for this time of year to the east and southeast of the islands, Birchard said.

American Red Cross officials are contacting volunteers and conferring with Civil Defense and the state Department of Education about potentially opening shelters at schools around the island, said Barney Sheffield, disaster manager for Hawaii Island.

“We’re calling volunteers, the shelter managers first, and trying to give them some kind of a time frame, but we know how hard that is with these systems,” Sheffield said. “We’re making sure they’re on-island and available.”

Oliveira said residents should keep in mind lessons learned from Tropical Storm Iselle and be prepared.

“One of the things we hoped everyone learned is that an ounce of prevention is worth 10 pounds of cure,” he said.

After Iselle made landfall over Puna last August, many residents were left in need of drinking water. A major issue was the use of catchment tanks for water. Without power, their pumps went offline. Oliveira said residents don’t have to buy water, but can fill containers they have at home.

Lengthy power outages, some lasting for weeks, left ice also in great demand following Iselle.

Keoni Jones, owner of Big Island Ice Co. in Kailua-Kona, said Monday his freezers were “kind of empty” following the Ironman triathlon, but he expects to be back to capacity by the time the storm strikes.

Jones donated ice to the Iselle relief effort and said he would be able to do so again if needed.

“Our machines run every day,” he said. “If we were called to take ice over, to donate ice … we’ll do whatever we need to do…”

Oliveira said his staff and other agencies have been in “response mode” for several months dealing with Iselle and, since then, the ongoing June 27 lava flow threat.

“The positive that comes out of that is we’re … still working very closely together and strengthening relationships and identifying lessons learned and gaps to close with the next storm event coming through,” he said.

Email Tom Callis at tcallis@hawaiitribune-herald.com.

Email Bret Yager at byager@westhawaiitoday.com.