"There is an increasing risk of two life-threatening impacts from Florence: Storm surge at the coast and freshwater flooding from a prolonged heavy rainfall event inland", the National Hurricane Center said Sunday.
The governors of North and SC and Virginia have already declared states of emergency, but winds and flooding caused by Florence could do serious damage even if it remains offshore.
Winds in Florence are now at 90 miles per hour, making it a category 1 hurricane.
Category 1 hurricane Florence gained strength on Sunday in the central Atlantic and is expected to turn into a major storm by Monday night as it churns over the open ocean and heads towards the U.S. East Coast, the U.S. hurricane agency said.
Gov. Henry McMaster told a news conference Sunday that people should "pretend, assume, presume that a major hurricane is going to hit right smack dab in the middle of SC and is going to go way inshore".
Cruise Hive will continue to keep readers updated on the latest developments of Hurricane Florence and Tropical Storm Isaac which are both in the Atlantic.
In South Carolina, Charleston city officials were offering sandbags for residents to fill. It poses no threat to land at the time, the center said. Myrtle Beach Mayor Brenda Bethune urged people to secure their homes but said it was too early to know if evacuations will be ordered.
Carnival Horizon which is the newest Carnival Cruise Ship has now canceled its scheduled port of call in Puerto Rico due to Florence which is now a category 1 Hurricane.
"Make your plans now", South Carolina Governor Henry McMaster urged residents during a news conference on Sunday.
North Carolina Governor Roy Cooper also urged his state's residents to get ready, noting the storm already was generating swelling waves and unsafe currents along the coast.
"The South Carolina Emergency Management Division tweeted Sunday that officials there are "preparing for the possibility of a large-scale disaster".
"On the forecast track, 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 States on Thursday", the NHC said Sunday.
Forecasters say Tropical Storm Florence has turned into a hurricane and is swirling toward the East Coast for what could be a direct hit toward the end of the week.
Hurricane-force winds extend outward up to 10 miles (20kilometers) from the center and tropical-storm-force winds extend outward up to 45 miles (75 kilometers). The storm was moving west at 14 mph (22 kmh) and expected to accelerate over the next 36 hours.
The National Hurricane Center says it is still too early to predict the hurricane's exact path, but a huge coastal area from northern Florida to North Carolina should prepare for a major hit.
Body of second person killed in Colorado River collision found
The head-on collision of two recreational boats on the Colorado River Saturday has left four people missing and 12 others injured. The crash happened in Moabi Regional Park , a popular water recreation area along the border about 290 miles east of Los Angeles.