Hurricane Hector strengthened to a Category 4 storm on Saturday as it churned toward the Central Pacific.
The storm had maximum sustained winds of 125 miles per hour and was moving west at 12 miles per hour.
The island will see a major impact from Hector, as hurricane force winds extend up to 40 miles from the center and tropical storm force winds 115 miles.
The Hawaii Coast Guard has set a port condition of "WHISKEY" due to the impending storm, during which time commercial traffic and transfer operations are allowed to continue.
There's a possibility the two storms could merge this week: Ileana should "begin weakening later on Tuesday and dissipate or become absorbed by John on Wednesday", the National Hurricane Center said.
Hurricane-force winds expected up to 30 miles from the center of the storm, while tropical storm-force winds reach up to 105 miles from the center.
"Very rough surf is expected to impact mostly south- and east-facing coastal areas of the Big Island", AccuWeather meteorologist Dan Kottlowski said.
The County of Hawai'i reports that the county is preparing for the arrival of Hurricane Hector in the Central Pacific region later this week. At this far distance, it can still change directions and avoid the Big Island of Hawaii altogether, but the high speeds of a hurricane combined with the erupting Kilauea volcano is a concern.
Officials urge that residents prepare an action plan if they need to shelter in place or evacuate their homes, and have an emergency kit with a minimum of 14 days of food, water and other supplies.