"While it is too soon to determine the location and magnitude of the worst impacts, all interests in Hawaii should continue to monitor the progress of Olivia, and use this time to prepare for the increasing likelihood of direct impacts from this system early next week", the center warned.
On Saturday, Olivia is forecast to be the fifth hurricane to enter the Central Pacific this hurricane season.
As of 5 a.m. today, the storm was about 735 miles east-northeast of Hilo and 900 miles east of Honolulu with sustained winds near 75 mph and was moving westward at approximately 16 mph.
Even if Olivia does not arrive with hurricane force winds, Caldwell said, "I don't think we should let our guard down".
The eye of the Category 2 storm was located about 1,375 miles east of Hilo, Hawaii, and 1,550 miles east of Honolulu, the NHC said in its 2 p.m. PDT update.
On Friday, the National Weather Service released its Hawaii area analysis that noted light and variable winds are "expected tonight through Monday, as Hurricane Norman passes northeast of the state. The seas and surf forecast over the middle part of next week will be highly dependent on the track and intensity Olivia takes as it nears the area". Norman was moving north-northwest at 9 miles per hour and had maximum sustained winds of 70 miles per hour.
Olivia would be the second tropical system to directly impact the Hawaiian Islands this year.
Mayor Kirk Caldwell this morning urged residents and visitors to remain vigilant about the threat of Hurricane Olivia and asked people not to hoard supplies. There isn't great agreement on how fast it will turn, however, due to the forecast depth of Olivia.
They say because of global warming and higher water temperatures farther north, along with signs of El Niño, hurricanes are now following a new and more menacing route.