Iselle, a Category 1 hurricane with maximum winds of 75 miles per hour (120 kph) , was about 175 miles (280 km) east of the Big Island by noon local time and was forecast to make landfall on Thursday night before passing south of the state's smaller islands on Friday.
As residents and tourists alike braced for Iselle to make landfall, Hurricane Julio was gaining momentum further east, and was expected to pass near Hawaii's islands by late Saturday or early Sunday, said Ray Tanabe, acting director of the National Weather Service in the Pacific region.
The rare threat of back-to-back hurricanes sent Hawaii residents scrambling to stock up on supplies as state officials warned of the potential for flash floods, mudslides and power outages in the normally calm tourist haven.
Governor Neil Abercrombie signed an emergency proclamation, freeing up funds and other resources, in anticipation of the storms' arrival, and authorities advised residents to prepare seven-day disaster supply kits.
"We are already seeing winds over 30 mph (48 kph) on parts of the Big Island. They are being sped up by terrain," Tanabe said. "We expect the center of the storm to move onshore between 8 p.m. and 10 p.m. this evening."
"It should be sunrise tomorrow by the time it clears the entire Big Island," he said.
SUN AND RAIN
In Honolulu, where the sun was still shining on Thursday morning, resident Don Riseborough said he was taking the weather in stride.
"Talk about the calm before the storm. It's a gorgeous day here, bright sunshine, nice trade winds, a beach day. The furniture is off the lanai, and I'm about to eat everything in the refrigerator in case the power goes out ... oh, and I have plenty of water, wine and beer.”
But on the Big Island, a downpour soaked customers who dashed from their cars to the Sunshine True Value Hardware store in the community of Kapaau, only to discover shelves already picked clean of batteries, flashlights, duct tape and plywood. But sales clerk Caryl Lindamood tried to spread a cheerful outlook.
"Mother Nature sure does like to stir things up for us, doesn’t she?" she said, joking about both the incoming storms and a light 4.5 magnitude earthquake that struck the Big Island 12 miles (19 km) west of Waimea on Thursday morning.
Elsewhere on the Big Island, Kailua-Kona resident Lisa Hummel, 44, said she and her family were filling every available container with water and had amassed batteries, candles and flashflights and plan to take shelter in their basement when the hurricane arrives.
"We'll probably make a pot of chili and ride it out," she said.
Markus Schale, general manager of Hotel Wailea on Maui, said his staff was removing all outdoor furniture from patios and around the swimming pool.
"We're delivering food and drinks to people's rooms before the storm, a sort of picnic service in the afternoon so they can stay in their rooms safely tonight," he said.