The Category 4 storm is expected to weaken a little as it approaches the islands, but the storm is expected to maintain hurricane strength. Unlike other parts of the USA where residents can get in their cars and evacuate, Hawaiians are confined to the islands and so sit waiting for the storm to hit.
The storm, which has maximum sustained winds of 130 mph, was in the Pacific about 210 miles south-southwest of the town of Kailua-Kona in the early hours of Thursday morning, according to CNN.
Residents of the Big Island have been in a state of alarm for three months since the eruption of the Kilauea volcano, which has forced thousands of residents from their homes as the lava flow spreads.
Packing 155-mile-per-hour (250-kph) winds, the storm could dump as much as 20 inches (50 cm) of rain over parts of the archipelago, triggering major flash flooding and landslides, according to the National Weather Service.
The last storm to inflict serious damage on Hawaii was 1992's Hurricane Iniki.
All of the islands are under weather alerts. The islands of Kauai and Niihau remained on hurricane watch and could face similar conditions starting Friday morning.
The president issued the declaration on Wednesday. It appears that the storm will not directly hit the island, but run directly parallel to it.
Federal officials have been working with Hawaiian utility managers to keep a close eye on the power grid, a major vulnerability in Puerto Rico past year when it was hit by Hurricane Maria, a Category 4 storm.
Honolulu police officers, state officials and outreach workers canvassed various communities to warn Oahu's homeless population about Hurricane Lane and urge them to seek shelter. "We are grateful to the President and FEMA for the swift approval of our request as our state braces for the severe weather ahead", the governor said.
Hurricane Lane, threatening a direct hit as Hawaii's worst storm in a quarter century, churned towards the main island of Oahu on Thursday as schools, government offices and business closed while residents stocked up on supplies and boarded up homes.
The downpours could lead to landslides and flooding.
Another important threat is storm surge. "Although the official forecast does not explicitly indicate Lane's center making landfall over any of the islands, this could still occur".