"Life threatening impacts are likely" to hit Hawaii, regardless of whether the storm makes landfall, NWS said in a statement.

Authorities warned residents of major flash flooding, landslides and mudslides, "even in areas not usually prone to flooding". Forecasts predict more than 20 inches (50cm) of rainfall.

Rip currents, rough surf, and waterspouts are also concerns along the coasts, particularly on the right side of the storm.

Governor David Ige signed an emergency proclamation ahead of Lane's onset, as "the danger of disaster is of such magnitude to warrant pre-emptive and protective action".

On Twitter, he urged residents to prepare for the storm and said he had "never seen such dramatic changes in the forecast track as with Hurricane Lane".

Honolulu residents stock up on gas and essentials as Hurricane Lane approaches 

Lisa Bucci, a scientist with the National Oceanic and Atmospheric Administration (NOAA), shared a video of Hurricane Lane from a research plane, noting: "It's a strong and dangerous storm."

In the state's history, only two storms of this strength have ever come within 350 miles (563 km) of the islands, according to the NWS.

Hurricanes rarely hit the Central Pacific region, due to currents and water conditions. These storms have always been more common in the eastern US.

According to NWS, only four named storms have made landfall in Hawaii since 1959 - and only two of those storms were hurricanes.

Hawaii generally sees about one storm strong enough to earn a name pass within 60 miles of the islands every four years.

Earlier this month, Hurricane Hector, a category four storm, also passed by the islands, though it did not come as close as Lane.

The Aloha state has also seen serious volcanic eruptions this summer, with lava and ash spewing from the Kilauea volcano on the Big Island since May.