ATLANTA — The powerful post-tropical cyclone Hermine lurked off the Eastern Seaboard on Sunday, and its evolving path made the storm more likely to be a bother than a threat.
Yet even as the storm churned hundreds of miles from the shoreline and positioned itself farther east than anticipated, officials, fearful of floodwaters and skeptical of shifting forecasts, often kept beaches closed, roads shut down and Labor Day weekend concerts canceled.
“It’s gone east, it could wobble back west or wobble further east,” said Gov. Chris Christie of New Jersey, who on Saturday declared emergencies for three counties. “All those things will decide what impact it has, especially in our coastal areas.”
By Sunday evening, the National Hurricane Center said the storm, which made landfall on Friday in Florida as a Category 1 hurricane, was about 335 miles east of Ocean City, Md.
A “slow north-northwestward motion” was predicted through Monday, and the hurricane center said Hermine’s center would “meander slowly offshore of the Mid-Atlantic coast for the next couple of days.”
Tropical storm warnings were in effect between the Fenwick Island, Del., area and Cape Cod, Mass., and the hurricane center described a storm system with tropical storm-force winds — between 39 and 73 miles per hour — extending more than 200 miles from its center. Hermine had maximum sustained winds on Sunday of 70 m.p.h., and the hurricane center said the storm was “expected to be at or near hurricane strength” before beginning to weaken on Monday night.
But to the federal and state authorities, wind speed was only part of the riddle of Hermine, which seemed ready a little over a week ago to disintegrate without becoming a named storm.
Flooding always loomed as a threat, and some forecasters predicted record-breaking events. On Sunday, after extensive preparations, those fears mostly eased with every passing hour.
“This is certainly not Sandy, nowhere near that,” Mr. Christie said, referring to the catastrophic 2012 storm. “And it’s not even Jonas.”
On Long Beach Island, to the north of Atlantic City, Christian Gagliardi, who has a six-month rental on the island, said he was not worried about the storm.
“Even if it stalls at this point, unless you live on the ocean, it’s not going to be a problem,” Mr. Gagliardi, 43, said while standing on a dune that was built to protect the island after Sandy.
Drivers approaching the island on Route 72 from the west were greeted with electronic signs warning “Severe Coastal Storm — Be Prepared,” and a convenience store near the causeway connecting the island to the mainland had placed a small pile of sandbags near its door.
The governors of Delaware, Maryland and Virginia also declared emergencies for at least parts of their states, and in New York, Gov. Andrew M. Cuomo’s office said the National Guard was on alert.
New York City banned swimming, bathing and surfing on its beaches through Labor Day, and the city said the restrictions could extend into Tuesday. The city also warned that it could limit access to bridges, and that Staten Island Ferry runs could be delayed or canceled.
The storm’s shift to a slow churn off the Mid-Atlantic coast followed itsdestructive and deadly march through Florida, Georgia and the Carolinas. Although officials in Georgia, North Carolina and South Carolina reported mostly limited damage, Gov. Rick Scott of Florida said on Sunday that electrical service issues remained a problem in Leon County, which includes Tallahassee, the state capital.
Mr. Scott’s office said more than 40,000 customers were still without power there, and in a pointed statement on Sunday, Mr. Scott mentioned issues that he called “still unresolved by city and county government.”
“There are still too many people without power in the City of Tallahassee and Leon County and, as you would expect, I will not be satisfied until it is fully restored,” Mr. Scott said.
Local officials have defended their response amid what Mayor Andrew Gillum of Tallahassee described over the weekend as an “unfortunate and irritating situation.”
“Our No. 1 priority is to get power back to our residents and businesses as quickly as possible,” he wrote in a lengthy post on Facebook. “Once we’ve successfully done that, we’ll worry about cleanup and getting Tallahassee back to the beautiful community that we have all grown to love.”
Also on Sunday, officials in Pasco County, north of Tampa, oversaw a blend of mandatory and voluntary evacuations in response to the rise of the Anclote River. Deputies helped people to evacuate, and prisoners were assigned to fill sandbags.
Officials have attributed two deaths — one in Florida and another in North Carolina — to the storm.