Forecasters say Florence is now a tropical storm but will continue to threaten North and South Carolina with powerful winds and catastrophic freshwater flooding.

Its top sustained winds have dropped to 70 mph (110 kph), and it's at a near standstill, moving west at just 3 mph (6 kph).

At 5 p.m., Florence was centered about 50 miles (75 kilometers) west-southwest of Wilmington, North Carolina, and about 25 miles (45 kilometers) northeast of Myrtle Beach, South Carolina.

Tropical storm-force winds extend outward up to 175 miles (280 kilometers) from its center. The National Hurricane Center says Florence is producing tropical storm-force wind gusts in Florence, South Carolina, about 60 miles from the coast.

President Donald Trump is preparing to travel to areas affected by Florence next week. 

White House press secretary Sarah Sanders says Trump will travel to the region "early to middle of next week."

She adds his trip will take place "once it is determined his travel will not disrupt any rescue or recovery efforts."

Aides say Trump has been monitoring the massive storm from the White House, and he has taken to Twitter to encourage those in its path to listen to their local authorities for how best to remain safe.

The storm, blamed for at least three fatalities, has inundated parts of the Carolina coast with heavy rain and high winds.

The storm came ashore early Friday as a Category 1 Hurricane., pounding the state with torrential rain and high winds.

Forecasters have been predicting catastrophic flash flooding. The National Hurricane Center in Miami says more than 16 inches of rain have fallen at locations in southeast North Carolina and another 20 to 25 inches is on the way.

Meteorologist Ryan Maue of weathermodels.com calculates that Florence could dump about 18 trillion gallons of rain in seven days over the Carolinas and Virginia, Georgia, Tennessee, Kentucky and Maryland.

That doesn't quite measure up to the 25 trillion gallons Harvey dropped on Texas and Louisiana last year. Maue says Harvey stalled longer and stayed closer to the coast, which enabled it to keep sucking moisture from the Gulf of Mexico.

Still, 18 trillion gallons is as much water as there is in the entire Chesapeake Bay. It's enough to cover the entire state of Texas with nearly four inches (10 centimeters) of water.

That much rain is 2.4 trillion cubic feet (68 billion cubic meters). It's enough to cover Manhattan with nearly 3,800 feet (1.1 kilometers) of water, more than twice as high as the island's tallest building.

North Carolina alone is forecast to get 9.6 trillion gallons, enough rain to cover the Tar Heel state in about 10 inches (25 centimeters) of water.

Maue calculates that 34 million people will get at least 3 inches, with more than 5.7 million getting at least a foot and about 1.5 million getting 20 inches or more.

Coastal and river communities on the north side of Florence are getting the worst of the flooding as the hurricane swirls onto land pushing a life-threatening storm surge.

Meanwhile, Energy Secretary Rick Perry says the U.S. electricity sector has been well prepared for Florence even as hundreds of thousands of homes lose power in the storm.

Speaking during a visit to Moscow less than an hour after the hurricane made landfall in North Carolina, Perry says "we've done this many times before. We know how to manage expectations. We know how to prepare our plants for these types of major events."

Perry says his department has been in contact with power companies and gas pipeline operators. He says that "over the years the state government and the federal government have become very coordinated in their ability to manage the pre-deployment of assets (and) the response to the citizens of those states, and we will soon be into the recovery."

More than 415,000 homes and businesses were without power Friday morning according to poweroutage.us, which tracks the nation's electrical grid.

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