Tropical Storm Olivia is expected to move over Hawaii Wednesday or Thursday, KHNL reported.
We've pulled together some of the key elements that explain why officials are so anxious, and what damage Florence could cause. On Tuesday (September 11), they published a map to their Facebook page showing the extent of the likely wind damage brought to the United States as Florence penetrates the Eastern seaboard.
According to the National Hurricane Center, the eye of the hurricane will likely not blow ashore until Friday afternoon local time, after which it will then push westward and bring with it the potential for catastrophic inland flooding.
It's unclear exactly how many people fled, but more than 1.7 million people in the Carolinas and Virginia were warned to clear out.
So how are these people preparing? The problem is, Flo is now expected to stall out over the Carolinas before slowly moving inland. It's a big one'.
He said during a reception for Congressional Medal of Honor recipients at the White House: 'We're getting tremendous accolades from politicians and the people but we are ready'.
More than 1 million people are under mandatory evacuations in the Carolinas and Virginia, and about 30 million across the Southeast will be affected if the forecast holds, CNN meteorologist Michael Guy said.
Florence could do more than $170bn (£130bn) of damage and affect almost 759,000 homes and businesses, says analytics firm CoreLogic.
North Carolina officials evacuated long-term care facilities and hundreds of prisoners in vulnerable areas, and also closed state parks, museums and other attractions.
The power companies expect millions of people to be without power for days.
When it reaches the coastline, it could sit around for days, unloading life-threatening storm surge, unsafe winds and flooding rain.
Most of Georgia is included in a cone of possible impact from the powerful storm, which has been downgraded to Category 3 but that is expected to cause significant damage as it moves off the Atlantic Ocean.
Waves 83 feet high were measured near the eye of Florence, according to a tweet from the National Hurricane Center.
There have been warnings that any flooding of hog manure pits, coal ash dumps and other industrial sites could have a lasting effect on communities, with tainted water possibly washing into homes and drinking supplies.
Hurricane warnings are in effect for the South Santee River in SC to Duck, North Carolina, and Albemarle and Pamlico sounds. In 1999, Hurricane Floyd barrelled into the region and flooded vast areas with toxic water.
On Instagram, parenting blogger Chrissy Marie, based in North Carolina, posted a photo of her kids' hurricane party, complete with bright pink balloons. "Protection of life is the absolute highest priority and that's what we are doing". "What can you do?"
"There's nothing you can do to stop it, so if you have to die, die happy", she said.
A delicatessen owner in the same town told Reuters that he was also going to stay.
"I'm not approaching Florence from fear or panic", said Brad Corpening, 35, who planned to ride out the storm in his boarded-up delicatessen in Wilmington.
"People go through a lot of stress because of what could happen to their property, their workplace, their vehicles".
"Were just trying to plan for the future here, not having a house for an extended period of time", David Garrigus said. "Persons located within these areas should take all necessary actions to protect life and property from rising water and the potential for other unsafe conditions", the hurricane center briefing said.