Maui hunkered down for heavy rains and powerful winds as a gradually weakening tropical storm barreled toward Hawaii, while Honolulu hoped it would be spared the worst.
Forecasters said Tropical Storm Olivia could dump 5 to 10 inches (12 to 25 centimeters) of rain, with some places getting as much as 15 inches.
Maui Mayor Alan Arakawa urged residents to store drinking water and warned that they should plan for power outages, landslides, high surf, fallen trees and flooded roads.
"Nature has a real funny way of not giving us advance notice," Arakawa said.
Olivia was about 100 miles (160 kilometers) east of Maui and packing winds of 50 mph (85 kph) late Tuesday. The storm, which was a hurricane earlier in the week, has been slowly losing power as it nears the state.
Schools, courts and government offices will be closed in Maui County on Wednesday in preparation for the storm.
Scott Zaffram, a senior response official with the Federal Emergency Management Agency, said emergency teams and supplies were ready on Maui.
The National Guard has mobilized personnel and trucks to the east side of Maui, said Herman Andaya, administrator of the county's emergency management agency.
Hawaiian Airlines cancelled flights by its commuter airline, Ohana by Hawaiian.
Officials were worried about landslides in west Maui because brush fires during Hurricane Lane three weeks ago wiped out vegetation, Maui County spokesman Rod Antone said.
Maui's Costco was a "packed house" all day Monday, but the stream of customers slowed by Tuesday afternoon, said general manager Tony Facemire. Lines at the gas pumps remained long Tuesday, he said.
The store was well-stocked with most items, but was out of lanterns, flashlights and generators, he said.
The owner of the only hardware store in the small town of Hana on the east side of Maui said he was determined to stay open so residents could buy tarps, screws or other supplies for their homes.
"I think it's important for us to try to stay open as much as possible, without jeopardizing the well-being of our staff," said Neil Hasegawa, owner of Hasegawa General Store.