Coastal Flood Advisory Issued: Which Shorelines Are at Risk and What You Must Do Now

A surge of king-tide water, strong onshore winds and an approaching hybrid coastal storm are prompting National Weather Service offices from the Carolinas to New England to post a Coastal Flood Advisory through at least Sunday, December 7 — with some zones likely to be upgraded to warnings as the system strengthens. Forecasters say minor to moderate inundation of 1 – 3 ft above normally dry ground is possible at the times of high tide, especially in low-lying neighborhoods along tidal creeks, sounds and back bays. Why flooding risk is rising • King tides: December’s perigean-spring-tide cycle is already pushing astronomical tides 6-10 in. higher than average. • Long-duration northeast fetch: A slow-moving “tropical wind and rainstorm,” possibly Subtropical Storm Lorenzo, will funnel 25-40 mph easterly winds toward the Atlantic shoreline, piling water against inlets and barrier islands. • Building surf: Offshore wave heights are forecast to reach 10-20 ft. Beach erosion and dangerous rip currents are likely from Cape Hatteras to Cape Cod. Timing by region • North Carolina & southeast Virginia: First round of nuisance flooding at Friday morning high tide; moderate flooding possible Friday night into Saturday as onshore winds peak. • Delmarva & southern New Jersey: Highest water levels expected Saturday evening and early Sunday. Route 1 causeways and coastal evacuation routes could be intermittently closed. • New York City & Long Island: Water may overtop portions of the FDR Drive, Belt Parkway and Meadowbrook/Ocean Parkway late Saturday night; wave run-up could breach newly restored dunes at Rockaway Beach. • Southern New England: Surge of 1-2 ft plus 15-20 ft breakers could coincide with Sunday’s midday high tide, raising the threat of road washouts on Cape Cod and Nantucket. What residents should do now 1. Move vehicles and outdoor equipment to higher ground at least six hours before local high tide. 2. Secure boats: double-up mooring lines; avoid low marina parking lots prone to splash-over. 3. Stay off jetties and piers; high-energy surf can sweep observers into the water. 4. Sign up for Wireless Emergency Alerts and monitor NOAA Weather Radio for potential escalation to Coastal Flood Warning. 5. Have alternate travel routes; even a half-foot of salt water can stall a car and corrode brakes. Infrastructure concerns Emergency managers warn that prolonged salt-water inundation could compromise septic systems, erode roadway sub-bases and flood electrical substations. Beach-renourishment projects completed after last summer’s hurricane episodes face a renewed risk of washouts, and several Outer Banks homes already undermined by September’s storms remain vulnerable to collapse into the ocean. Outlook beyond the weekend Models show the storm’s core stalling near the Delmarva Sunday night before curving out to sea. That means minor tidal flooding may persist through at least Monday in back-bay communities where water drains slowly. A reinforcing cold front arriving mid-week could tighten the pressure gradient and generate another round of gale-force onshore winds; residents should be prepared for additional advisories. Key take-away The combination of king tides and a strengthening coastal storm makes this weekend one of the highest coastal flood threats of the winter season so far. Even if you’ve weathered recent nor’easters without problems, plan for higher water levels, road closures and beach erosion through Sunday night.