On Sunday afternoon, Olivia was about 595 miles east-northeast of Hilo and was narrowly registering as a Category 1 hurricane moving west at 12 mph with maximum sustained winds at about 75 miles per hour.
"Rapid strengthening is forecast, and Florence is forecast to become a major hurricane this morning, and is expected to remain an extremely unsafe major hurricane through Thursday", it said.
"North Carolina is taking Hurricane Florence seriously, and you should too", Cooper said Monday.
The storm is expected to reach SC and North Carolina later this week.
"There is an increasing risk of life-threatening impacts from Florence: storm surge at the coast, freshwater flooding from a prolonged and exceptionally heavy rainfall inland and damaging hurricane-force winds", a 5 a.m. advisory said.
Some meteorologists are already predicting that Florence "could be one of the worst storms in us history".
The mandatory evacuation orders in SC take effect on Tuesday at noon in eight counties along the state's 187-mile coastline. Tens of thousands of people are also expected to seek higher ground along coastal areas of North Carolina. And we are heading into the peak with three hurricanes churning in the Atlantic.
All inland residents should find out now if you live in a flood prone area.
Should Florence make landfall as a Category 4, it would be the first Category 4 hurricane since Hazel in 1954 to hit North Carolina.
Further east, forecasters are watching Hurricane Helene and Tropical Storm Isaac in the Atlantic, and a patch of showers in the western Caribbean, which has a 30 per cent chance of becoming a cyclone in the next 2 days.
It added that the hurricane should approach the USA coast by Thursday.
NOAA Hurricane Florence is forecast to hit the northeast coast later this week.
Maui County is expected to experience tropical storm-level winds starting Tuesday.
Florence would reach Category 5 with sustained winds of 157 miles per hour or greater.
Hurricane Harvey killed 68 people and caused catastrophic flooding in Houston, while Hurricane Irma caused 129 storm-related deaths in Florida, Georgia and North Carolina.
"We are not going to gamble with the lives of the people", McMaster, a Republican, said.