An offshore storm is pushing flooding into New Jersey’s back bays

An early-season nor’easter developing off the coast is pushing minor to moderate tidal flooding into New Jersey’s back bays, with Barnegat Bay and the Shrewsbury River named as the areas facing the most persistent flooding through the weekend. The National Weather Service’s Philadelphia/Mount Holly office, in a briefing dated September 24, warned of sustained winds of 25 to 35 mph and gusts up to 50 mph along the New Jersey and Delaware coasts as the storm’s track remains uncertain. A Coastal Flood Warning issued the same day covers Ocean, Atlantic, Cape May and southeastern Burlington counties through Saturday morning.

Named bays facing the worst of the tidal push

Beyond Barnegat Bay and the Shrewsbury River, the briefing lists Indian River Bay in Delaware, along with Delaware Bay, southern Raritan Bay, the tidal Delaware River and Chesapeake Bay, as waterways likely to see repeated rounds of tidal flooding as the storm sits offshore. The Coastal Flood Warning describes one to two feet of inundation above ground level in low-lying areas near shorelines and tidal waterways, with widespread roadway flooding expected in coastal and bayside communities and some roads becoming impassable.

Forecasters flagged Barnegat Bay specifically as the spot where flooding could climb from moderate toward major levels if the storm’s track holds close to shore, according to the Mount Holly office’s warning text, a distinction drawn because back bays like Barnegat drain more slowly than open ocean shoreline once water piles in. That slower drainage is also why the warning’s clock runs through 2 a.m. Saturday rather than closing after a single high tide.

A meteorologist who is not ready to call it over

Lee Robertson, lead meteorologist at the National Weather Service’s Mount Holly office, told The Philadelphia Inquirer the storm “could be slow to pull out,” adding that the region may not be past the worst of it until Monday. AccuWeather senior meteorologist Bill Deger offered a similarly unsettled outlook, saying “mother nature looks like it isn’t going to cooperate very much” as the storm’s exact path remained in flux less than two days out.

That uncertainty is baked into the forecast language itself. A Patch report quoted the National Weather Service saying “there is still a large amount of uncertainty with the storm track into the weekend,” a caveat that explains why the warning window keeps extending rather than narrowing as landfall approaches.

Wind, surf and a record-strength high pinning the storm in place

Rutgers University atmospheric science professor Steve Decker pointed to an unusual atmospheric setup steering the system: a high-pressure area over Quebec that he said might be the strongest on record in data going back to 1979. That blocking high is part of why forecasters expect the coastal storm to stall rather than move through quickly, prolonging the flooding threat across multiple tide cycles instead of a single peak. Seas offshore are forecast at 8 to 15 feet, with gale-force winds and the potential for storm-force gusts across coastal waters, according to the Mount Holly briefing.

A regional wind advisory tied to the same system covers the mid-Atlantic more broadly, with gusts reaching 40 to 50 mph as far south as coastal Maryland and Virginia and a high wind watch for gusts up to 60 mph farther north on Long Island and into New England. High rip currents, dangerous surf and significant beach erosion are expected up and down the coast, with possible dune breaching in the most exposed spots. Inland Philadelphia is forecast to see far weaker effects from the same system, with gusts generally topping out near 25 to 30 mph, underscoring how much of this storm’s punch is concentrated along the immediate coastline rather than spread evenly across the region.

Atlantic City bracing for a run of high tides

Atlantic City’s forecast lays out a specific sequence of dangerous high tides: near or at moderate flood levels around 7 p.m. Friday, then again at 8 a.m. and 8 p.m. Saturday, with streets expected to fill with up to a foot of water. Ocean City’s back bay areas are forecast to reach moderate levels at 8 p.m. Friday and again at 8 a.m. Monday, while the tidal Delaware River faces minor flooding across four consecutive high-tide cycles starting at 1 a.m. Friday.

Atlantic City Mayor Marty Small Sr. predicted heavy shoreline damage from the repeated tides, telling the Inquirer the city should brace for “a lot of beach erosion.” Atlantic City Emergency Management Chief Scott Adams described the threat as a sustained one rather than a single event, saying “it’s not a one-two punch,” a framing that matches a storm forecasters expect to linger through the weekend and, in Robertson’s own estimate, possibly into Monday before New Jersey’s back bays finally drain clear.

This article was produced with the assistance of AI and reviewed by Morning Overview editors prior to publication.

More from Morning Overview