Hurricane Ana further intensified this afternoon with winds around 80 mph as it approached Hawaii.
At about 5 p.m., the storm's winds held at 80 mph, slightly above the category 1 hurricane status of 74 mph winds. The storm was 185 miles south-southwest of Kailua-Kona, and 310 miles south-southeast of Honolulu, moving to the west-northwest at 13 mph. The tropical storm force winds extend 105 miles — 20 miles farther out than earlier Friday afternoon — from the center and hurricane force winds extend out 25 miles.
The storm is expected to pass 150 miles southwest of the Big Island Friday night and about 175 miles southwest of the rest of the island chain this weekend. The storm is also expected to take more of a northwest turn — closer to Hawaii — Friday into Saturday and slow down as it passes south of Oahu and Kauai Saturday night and Sunday.
Hurricane Ana could continue to strengthen Friday night before windshear gradually weakens it Saturday and Sunday.
"The window for intensification will close on Saturday," forecasters said. "But Ana will remain a dangerous tropical storm."
A tropical storm watch and flood watch is in effect for the Big Island. Forecasters expect heavy rains with the chance of thunderstorms, gusty winds, and rough surf as the storm passes the island Friday night.
The National Weather Service also posted tropical storm watches for Oahu, Maui and Kauai counties and surrounding waters.
Forecaster said the storm should be far enough south that winds will not reach tropical storm strength on the main Hawaiian islands.
But, they caution that "only a small change in the track of Ana could result in higher winds on Saturday. ... It is still too soon to try to nail down details."
All islands will get high, rough surf on southern shores. Gusty winds that could down trees and cause power outages, and heavy rains with the potential for flooding and mudslides are also possible.
The storm will pass closest to Maui County on Saturday and should move south of Oahu Saturday night. Kauai will see the storm's greatest impact on Sunday.
The storm could dump up to 12 inches of rain in some areas of the Big island. But most areas should see 6 to 8 inches. Surf of 10 to 12 feet from the storm was reported at South Point Friday and foreasters expect waves of up to 20 feet in Kau and Puna as the storm makes its closest pass to the island. The Kona Coast could also get 12-foot surf after the center of the storm moves west.
Oahu and Kauai County may also see 10 to 20-foot wave faces on Saturday on south shores and 3- to 7-foot surf on west and east shores. A northwest swell is also arriving, boosting north shore surf to 10 to 15 feet Saturday into Sunday.
South shores of Maui County could see 10- to 15-foot surf Saturday and Sunday.
The 11 a.m. forecast track puts Ana's path further south, with all islands except Niihau out of range for a direct hit.
But foreasters caution that people should not focus on the exact track of the storm.
"Only a slight shift to the right (closer to the Hawaiian islands) in the forecast track could mean signficant differences in the potential impacts to the main Hawaiian islands," forecasters said.
A high pressure ridge developing near Oahu and Kauai is likely to cause Ana to slow down and turn to the west, keeping the storm south of the islands.
But if the storm slows or stalls, the potential for more rain increases.
"The timing and extent of this turn has significant implications as to the potential impacts in the islands this weekend," foreasters said.
As of Friday morning, forecasters predicted some areas of Maui, Kauai and Oahu could get up to 8 inches of rain over the weekend. Most areas of Maui County should get between 2 to 4 inches and 3 to 6 inches could fall on Oahu and Kauai.
The forecast for southern shores of Oahu, including Honolulu, calls for a 50 percent chance of rain and potentially heavy rain, including thunderstorms Friday afternoon into Friday night as Ana's outer rain bands reach the island.
Saturday will bring frequent showers and the chance of thunderstorms through Sunday. Winds of 20 to 25 mph, with 35 mph gusts are possible through Sunday night as Ana passes south of the island. The chance of rain is 90 to 100 percent through Monday.
Maui and Kauai counties can expect similar weather, with the timing sooner for Maui and later for Kauai, as Ana makes its closest approach to those islands.
Ana will likely leave muggy Kona weather and showers in its wake as it moves northwest away from the state. The humidity and rainy weather could stick around through the middle of next week.
National Weather Service meteorologist Eric Lau said the winds can still down power lines and cause a lot of damage and rains, especially if they stall, could create flooding. The storm surge can also cause damage along the coast.
"Even a 40 mph wind is pretty strong," Lau said. "Torrential rains would be cause for flash flooding, especially for people in low-lying areas."
The weather service and civil defense officials say people should have their emergency kits stocked and be ready for the storm.
"People should be prepared for potential impacts," Lau said. "It could potentially be a dangerous storm."