Heavy rains of 12 inches (30 centimeters) or more hit the southeast coast of North Carolina on Monday as an unnamed storm moved ashore and headed toward the mid-Atlantic and Northeast.

The National Hurricane Center is calling it a potential Tropical Cyclone 8 and said in forecast updates that the front will weaken as it moves across the country overnight.

The region may already have been hit by the worst of the disruptions. A National Weather Service station measured 18 inches of rain at Carolina Beach on Monday, causing city offices and the recreation center to be closed, a statement said.

Carolina Beach State Park was also closed all day, park officials said. U.S. Highway 17 south of Wilmington also was closed, state and local officials said.

According to the weather service, similar volunteer weather stations at other locations along the coast, including Military Ocean Terminal Sunny Point in Southport, reported more than 14 inches of rain.

According to a meteorologist with the National Weather Service, it is too early to say whether the amounts have reached record highs. The weather service in Wilmington will probably answer that question late Tuesday morning.

Flooding has damaged buildings in New Hanover County on the southeast coast, Gov. Roy Cooper’s office said.

“We are seeing severe flooding due to heavy rainfall, so please avoid driving on flooded roads,” Cooper said in a statement Monday.

Flash flooding was confirmed in the community of Kelly, about 38 miles inland from Wilmington, the weather service reported. A road was closed there as a result, it said.

Several roads in Brunswick County were washed away. The sheriff’s office shared photos of roads that had become waterways or were impassable due to missing chunks of asphalt.

On Monday afternoon, the National Weather Service in central Brunswick County warned residents to take cover because “a severe thunderstorm capable of producing a tornado” was threatening the area near Leland, according to a tornado warning that has since expired.

Tornado warnings for Emerald Isle, Swansboro, Cape Carteret and Cedar Point expired early Monday night. It was unclear whether any tornadoes touched down, and the weather service typically doesn’t verify them until the next day; it sends ground observers to possible locations when it’s safe to do so.

The North Carolina Transportation Department reported multiple road closures due to the weather and said the Cherry Branch-Minnesott Beach and Bayview-Aurora ferries suspended operations Monday.

The governor’s office reported road closures due to the weather in Sampson, Duplin, Brunswick, New Hanover, Onslow and Pender counties.

The state’s Emergency Operations Center was placed in an “enhanced” operational mode, Cooper’s office said, and the state’s emergency response teams were standing by to respond as needed.

On Monday evening, the weather service in Wilmington reported that the worst of the front had passed.

“The heavy rainfall has ended,” a statement said of the flash flood. “Flooding is no longer expected to be a threat.”

The disturbance was 45 miles west of Cape Fear and was moving northwest at 7 mph, the National Hurricane Center said in its latest advisory. Maximum sustained winds have decreased to 35 mph; earlier in the day, the weather service’s volunteer station at Military Ocean Terminal Sunny Point measured a gust of 77 mph.

Sustained winds of 74 mph qualifies the storm for hurricane status. A small craft advisory, warning of “hazardous sailing conditions,” covered waters from Cape Hatteras to Ocracoke Inlet on Monday and remained in effect until Wednesday morning.

With wind gusts of up to 28 mph (45 kph) expected over the Atlantic Ocean, a National Oceanic and Atmospheric Administration buoy measured 11-foot (3.3-meter) waves off Cape Hatteras.

“Winds are expected to weaken further over the next day or so and the low pressure area is expected to dissipate over the Carolinas by Wednesday morning,” the hurricane center said in its warning.

Tropical storm warnings were in effect for 8 million people in the Carolinas on Monday.

NBC News meteorologists said the disturbance was expected to move across the central Appalachians, Virginia, West Virginia and Maryland on Tuesday, then bring showers to eastern Pennsylvania, Delaware, New Jersey and southern New York on Wednesday.

Meteorologists at Federal News and NBC News said the storm has not yet had enough time to move over the normally fertile waters of the warm Atlantic Ocean and develop into anything more powerful than a potential tropical cyclone.

Meteorologists say that once the storm makes landfall Monday night and moves northeast, it will disintegrate and have little chance of being named.