It was a potentially catastrophic Category 4 storm but was expected to keep drawing energy from the warm water and intensify to near Category 5, which means winds of 157 miles per hour (253 kph) or higher.
Hurricane Florence continues to grow in size and magnitude as it barrels toward the U.S. East Coast.
Since the hurricane has already amassed wind speeds of 130 miles per hour, the coast could see life-threatening wind, rain, and storm surges. It comes after he approved a similar declaration for North and SC, which are now in the bull's-eye of the powerful Category 4 storm.
Once it makes landfall, Florence is predicted to stall and remain over North Carolina for at least 24 hours - increasing the threat of unsafe flooding, NHC director Ken Graham said on Monday. The Windward Islands can anticipate 1- to 2-inches of rain.
Back in late August, the Atlantic tropics looked like they were going to stay boarded up for the season. As of 11 p.m. ET Saturday, Helene was located 155 miles southeast of the southern most Cabo Verde islands.
"We do not want to risk one SC life in this hurricane", Governor Henry McMaster told a news conference.
"The center of Florence will move over the southwestern Atlantic Ocean between Bermuda and the Bahamas Tuesday and Wednesday, and approach the southeastern coast of the United Sates on Thursday", the NHC said.
Isaac is a strong tropical storm with 60kt sustained winds, now about 675 miles east of the Lesser Antilles.
Trump has declared states of emergency for North and SC and Virginia, and canceled campaign events Thursday and Friday in anticipation of the storm. "We have to prepare and prepare to the fullest possible extent", he told a news conference.
"It's important to remember the cone of uncertainty covers the entire SC coast, meaning landfall in SC is still a possibilty", Quagliariello said.
Hurricanes Isaac and Florence continue to pose problems for Caribbean countries
The National Oceanic and Atmospheric Administration's Goes-East weather-monitoring satellite captured an eye-opening loop of Florence churning in the Atlantic.
The storm is now around 400 miles south of Bermuda and is moving at 16 mph (26 kph). "Storm surge and hurricane watches could be issued for portions of these areas by Tuesday morning", the NHC said, adding that at 11:00 a.m.
A warm ocean gives hurricanes their fuel, and Florence is moving over an area with water temperatures nearing 85 degrees (30 Celsius), hurricane specialist Eric Blake wrote.
Suddenly, we transported back to the middle of 2017's destructive and hyperactive season with three named storms in the Atlantic and two disturbances threatening to boost the tally.
In the Pacific, Olivia became a tropical storm again on a path to hit the Hawaiian islands early Wednesday.
The U.S. Navy said it was sending almost 30 ships from coastal Virginia out of port to ride out the storm.
The governor of Maryland has declared a state of emergency in preparation for significant flooding from Hurricane Florence.
"I think this is very Harvey-esque", said University of Miami hurricane expert Brian McNoldy.
In Guam, Typhoon Mangkhut - a Category 4 storm - narrowly missed dealing a direct blow to the island.
Hurricane Helene Continues To Gain Strength In Eastern Atlantic
Not only has the storm exploded in intensity, but its zone of hurricane-force winds approximately doubled in size Monday. Meanwhile, two other storms were also spinning in the Atlantic. "The building we're going to board some windows up".