IHEI, United States - Tourists and locals braced for double trouble in Hawaii on Thursday as a rare pair of hurricanes took aim at the holiday paradise, the first threatening a direct hit.
Big Island, the largest and most southerly of the volcanic island chain, was steeling itself for the imminent arrival of Hurricane Iselle, bringing strong winds, heavy rains and dangerous storm surges, the Central Pacific Hurricane Center (CPHC) warned.
In an unusual development, Iselle was being trailed by another, stronger hurricane dubbed Julio, with the prospect of a one-two punch putting the popular archipelago on even higher alert.
State authorities shuttered all non-emergency public facilities and sent employees home from midday. State offices were to remain closed Friday, while schools were being designated as shelters in the event of emergency evacuations.
Rain was already falling on the wind-turbine dotted arid northwest of Maui island, where locals say it almost never rains, and wind was picking up markedly.
The second largest Hawaiian island, Maui lies directly north of the Big Island and its 150,000 residents annually welcome 2.5 million tourists.
Even the public beaches closed down, although sun seekers jumped the waves, ignoring red flag warnings of hidden riptides.
Maui authorities banned dive and snorkel boats from setting out to popular areas, including the unspoiled half-sunk crescent-shaped Molokini crater famed for its undersea coral reef.
Some hotels and residential complexes closed their pristine pools, and disappointed guests found they could not rent boogie boards or paddleboards to brave the swelling waters of the Pacific Ocean.
"In 22 years here, I've never seen anything of this magnitude," store owner Tim White told AFP.
"Yesterday, some people were even scrambling to get out early ahead of the storms."
Packing maximum sustained winds of 75 miles (120 kilometers) per hour, Iselle - a Category 1 storm - was 70 miles southeast of Hilo and 280 miles east-southeast of the state capital Honolulu at 0600 GMT Friday, CPHC forecasters said in their latest advisory.
"On the forecast track, Iselle will be moving across the Big Island tonight (Thursday), and passing south of the smaller islands on Friday and Friday night," CPHC said, while residents and tourists took to social networking sites to describe how the storm was impacting them.
"Wind is getting kinda freaky. shutting down my reserve power now. stay safe everyone," wrote @DeniseLaitinen on Twitter.
Hours before the impact, Island Air announced it was cancelling all its inter-island flights from late Thursday and on Friday.
Hawaiian Airlines also dropped late Thursday connections, while United Airlines and US Air snapped links with mainland Los Angeles and Phoenix.
The haven for sun worshippers and water sports fanatics from around the world was expected to see rainfall of up to 12 inches (30 centimeters) thanks to Iselle.
"These rains could cause life-threatening flash floods, as well as rock and mud slides," the CPHC cautioned.
"We all need to stay alert, pay attention, and work with the emergency management agencies across the state," Governor Neil Abercrombie told a press conference.
Julio, the fourth major hurricane of the Eastern Pacific season, was about 1,000 miles east of Hilo, according to the latest update from the National Hurricane Center.
With the twin storms fast approaching, long lines had formed at local supermarkets, as residents and vacationers rushed to stock up on water, bread and batteries to see them through the next few days.
State authorities warned that price gougers would be severely punished.