At one point Sunday, nearly 6,000 Progress Energy customers were without power in Johnston County. Crews restored service by noon.
Progress Energy reported other smaller, sporadic power outages throughout eastern and central North Carolina. Duke Energy did not report any outages in those areas.
The National Weather Service issued the flash flood warning after between 1.5 and 4 inches of rain fell in and around Fayetteville. The warning expired at 10:30 a.m.
Sgt. Steve Bates, of the Fayetteville police, said the city saw a lot of high-standing water on streets and in other low-lying areas, but most receded by 9:30 a.m. Officers had to pull out a few cars that were caught in high water in the streets, and crews made repairs to some traffic signals, Bates said.
Emergency officials with the Cumberland County Sheriff's Office said they had not received any reports of flooding.
One emergency phone line has been restored, and the call center is using a manual backup to generate and dispatch calls for service.
"Dispatchers and communications staff have responded well, and the public should not notice any degradation of response time in emergency services," Sgt. S.G. Bates said in a news release.
The power surge that knocked out 911 service was possibly the result of a nearby lightning strike.
The NWS said that earlier Sunday, Cross Creek in downtown overflowed its banks, and a foot of water flowed down Ray Avenue.
Emergency officials got reports of flooding, including on Bragg Boulevard, Ramsey Street/U.S. Highway 401 and Russel Street. WRAL viewers also reported flooding along Fort Bragg Road and McPherson Street.
A frontal boundary could redevelop over central and eastern North Carolina around mid-day Sunday, creating a chance for more rain and thunderstorms in the afternoon.
Storms will likely be more numerous over the Sandhills and coastal plain, while the Triangle and areas north and west will likely see more spotty coverage, mixed with rain.
Rainfall totals from the overnight storms were variable. Several tenths fell at the Raleigh-Durham International Airport, but Fayetteville got nearly an inch by midnight.
At one point on Saturday, an inch of rain fell in less than 30 minutes.