(Adds polling places opened for voting)
By Malia Mattoch McManus
HONOLULU, Aug 9 (Reuters) - Hawaii voters went to the polls on Saturday for the state's primary election as authorities, as residents rushed to clean up debris from one tropical storm with only a day to prepare for a hurricane that was on its way.
Voters are to decide a Democratic primary contest between Governor Neil Abercrombie, who has a thriving economy on his side, and state Senator David Ige, who has surged to a double-digit edge in polls despite raising less campaign cash.
All but two polling stations on the east coast of the Big Island, hardest hit by Tropical Storm Iselle, opened on Saturday morning, election officials said.
"There weren't any substantial delays" facing voters, said Rex Quidilla, a spokesman for the state's Office of Elections.
Iselle weakened from a hurricane before it struck the Big Island on Thursday and lost more force as it later pushed past the U.S. state.
As thousands of residents scrambled to clear away debris from the storm, officials warned against complacency given the extent of the disruption and the uncertainty over the path of the bigger storm hurtling toward them.
Hurricane Julio, which was downgraded to a Category 2 storm on Friday, was packing maximum winds of 100 mph (155 kph) as it churned about 500 miles (800 km) off the Big Island city of Hilo and 685 miles (1,100 km) east of Honolulu, the state capital, the National Weather Service said on Saturday morning.
Forecasts showed Julio likely tracking about 150 miles (240 km) north of the archipelago early on Sunday at the earliest, meteorologists said. "Gradual weakening is forecast during the next couple of days, but Julio is forecast to remain a hurricane through Sunday night," said a Weather Service advisory.
There were no reports of major injuries from Iselle, a relief to a state heavily dependent on tourism. Some 95,000 tourists were visiting Oahu, the state's most populous island, when Iselle hit.
The American Red Cross said on Friday 900 people remained in evacuation shelters and a utility company said 9,200 customers on the Big Island were still without power on Friday at midnight.
"The air is thick with wood smoke since the power is still out," said Malia Baron, who was visiting the Volcano area of the Big Island. "It's been quite the adventure, but we're ready to head home to prep for the next storm."
The storm was responsible for a rare lull in campaigning.
As the election loomed, farmers on the largely rural Big Island were checking crops, fruit and macadamia nut trees for damage.
Ka'u Coffee Mill, a grower, said it closed on Friday as farmers assessed damage to fields from flooding.
"We took precautions to make sure things didn't blow away and to minimize damage if we in fact got high winds - but we didn't," said Bruce Corker, owner of Rancho Aloha coffee farm in Holualoa, in the Kona region.
Election analysts said it was unusual for an incumbent governor to struggle given the strength of the economy, with unemployment near a record low, tourism going well and state coffers sound.
Hawaii has consistently re-elected Democratic governors since Republican Bill Quinn was ousted in 1962. A late July poll of 458 likely voters conducted for the Honolulu Star-Advertiser put Ige 18 points ahead of fellow Democrat Abercrombie at 54 percent to 36 percent.
Abercrombie told supporters in a statement that Hawaii polls historically have often failed to presage actual results.
Supporters say Abercrombie has achieved much, signing gay marriage legislation into law, helping to negotiate a North Shore land conservation deal and championing development in downtown Honolulu. He also represented Hawaii in the U.S. House of Representatives from 1990 to 2010.
Ige's campaign issued emails urging voters to cast ballots early because of the storms. The winner will face Independent and Republican candidates in November's general election. (Additional reporting by Alex Dobuzinskis in Los Angeles and Ken Wills in Kapaau, Hawaii; Writing by Eric M. Johnson; Editing by Steve Orlofsky; Editing by Mark Heinrich, Sandra Maler and Steve Orlofsky)