* Storm now a Category 2 hurricane
* Water pushing in over coastal roads
* Intense storm surges, inland flooding expected
* 10 million people in potential disaster zone (Adds new timing and location of landfall)
WILMINGTON, N.C., Sept 13 (Reuters) - The outer bands of Hurricane Florence lashed the Carolinas with wind and rain on Thursday, flooding roads and overflowing rivers in an ominous prelude of the damage the huge storm could inflict when it makes landfall on Friday with millions of people in its path.
Florence, downgraded to a Category 2 storm on the five-step Saffir-Simpson scale, remained dangerous and unpredictable, the National Hurricane Center said. It was forecast to make landfall Friday morning or afternoon near Cape Fear, North Carolina, bringing up to 40 inches (1 meter) of rain in places.
"Hurricane Florence was uninvited but she's just about here anyway," North Carolina Governor Roy Cooper told a news conference, warning residents to stay vigilant despite the downgrade. "Stay on guard. This is a powerful storm that can kill."
Florence's maximum sustained winds were clocked on Thursday at 100 miles per hour (170 km per hour) as it spun in the Atlantic Ocean, down from a peak of 140 mph (224 kph) earlier this week when it was classified as a Category 4.
The community of Avon on North Carolina's Outer Banks barrier islands reported wind gusts of 74 miles per hour (119 km per hour), while Morehead City on the mainland coast had received 3.6 inches (9.1 cm) of rain in the past 13 hours, according to the National Weather Service.
Already some roads and intersections were inundated with water, making them impassable.
About 10 million people live in the storm's path and more than 1 million had been ordered to evacuate the coasts of the Carolinas and Virginia. Thousands have taken refuge in emergency shelters, officials said.
The storm's center was about 100 miles (160 km) southeast of Wilmington, North Carolina, at 3 p.m. EDT (1900 GMT) but already some 19,000 homes and businesses in the Carolinas and Virginia were without power by mid-afternoon. Millions of people were expected to lose power from the storm and restoration could take weeks.
TORNADOES, STORM SURGES PREDICTED
The National Hurricane Center warned the threat of tornadoes was increasing as Florence neared shore and South Carolina Governor Henry McMaster said the heavy rains could trigger landslides in the western part of his state.
Florence could bring wind-driven storm surges of seawater as high as 13 feet (4 meters) and NHC Director Ken Graham said on Facebook they could push in as far as 2 miles (3 km). Heavy rains were forecast to extend into the Appalachian Mountains, affecting parts of Alabama, Tennessee, Kentucky and West Virginia.
Emergency declarations were in force in Georgia, South and North Carolina, Virginia, Maryland and the District of Columbia.
Despite pleas from state and local officials, some residents rejected calls to evacuate.
Near the beach in Wilmington, a Waffle House restaurant, part of a chain with a reputation for staying open during disasters, had no plans to close, even if power is lost. It had long lines on Thursday.
In the tiny community of Sea Breeze near Wilmington, Roslyn Fleming, 56, made a video of the inlet where her granddaughter was baptized because "I just don't think a lot of this is going to be here" later.
In Wilmington, wind gusts were stirring up frothy white caps into the Cape Fear River.
"We're a little worried about the storm surge so we came down to see what the river is doing now," said Linda Smith, 67, a retired nonprofit director. "I am frightened about what's coming. We just want prayers from everyone."
Will Epperson, a 36-year-old golf course assistant superintendent, said he and his wife had planned to ride out the storm at their home in Hampstead, North Carolina, but reconsidered due to its ferocity. Instead, they drove 150 miles (240 km) inland to his mother's house in Durham.
"The anxiety level has dropped substantially," Epperson said. "I've never been one to leave for a storm but this one kind of had me spooked."
(Reporting by Ernest Scheyder Additional reporting by Bernie Woodall in Fort Lauderdale, Florida; Carlo Allegri in Wilmington, North Carolina; Mana Raibee in Sea Breeze, North Carolina; Anna Mehler Paperny in Washington, North Carolina; Brendan O'Brien in Milwaukee, Stephanie Nebehay in Geneva and Steve Gorman and Dan Whitcomb in Los Angeles Writing by Dan Whitcomb Editing by Bill Tarrant and Lisa Shumaker)