The U.S. East Coast is entering a period of rather unsettled weather as a developing nor’easter is strengthening offshore and is poised to bring heavy rain, damaging winds, dangerous surf and coastal flooding from the Mid-Atlantic all the way into New England. The worst of the system is expected from Friday through the weekend with the Northeast being the main area to feel the brunt of it.
.
The Calm Before the Turbulence
For the most part the coast will still probably seem quite quiet. A strong cold front with cooler high pressure is moving east and that will set the stage for a sharp temperature drop across much of the central and eastern US over the weekend and into next week.
But out at sea the atmosphere is starting to organise. A low is expected to strengthen along the coast, drawing on the very warm waters of the Atlantic. Sea surface temperatures off the Mid-Atlantic are at 81-83F (roughly 2-4.5F above normal) which is the kind of fuel that can help a coastal storm to deepen and intensify.
Friday: The Coast Turns Hostile
By Fri the storm’s effect should be very clear. Winds of 40-60 mph are expected along the coast from NJ to Maine with that strong enough to snap branches, blow down power lines and make travel difficult (particularly for high profile vehicles on bridges and exposed highways).
Rain will come in waves at times heavy enough to reduce visibility and overwhelm the drainage systems. Rainfall amounts are expected to be widespread at 2-4 inches with isolated amounts near 5 inches on Cape Cod. In the low lying areas that can mean flooded streets, vehicles stalled in the water and water seeping into homes and businesses.
The Ocean Strikes Back
The biggest threat may be the sea itself. Dangerous surf is expected along much of the NE coast through Friday-Sunday with coastal flooding possible along the Jersey Shore, Long Island, RI, Martha’s Vineyard, Nantucket and parts of coastal NH and ME.
Along the MA coast breaking waves of 6 to 17 feet are possible. Offshore seas near Jeffreys Ledge in the Gulf of Maine could get to 15 feet, turning the water into a wall of churning, wind driven spray.
Beach erosion is a real issue. If you have a sustained period of strong wind over a number of high tide cycles then the dunes and the shoreline protection can be eroded right away, leaving the roads, the boardwalks and the waterfront properties much more exposed to the next wave.
New England in the Crosshairs
New England is likely to be hit by the most severe combination of the storm’s hazards (wind, rain, coastal flooding and high seas). The system is slow moving so the misery is likely to be prolonged with communities remaining under bands of rain and gusty onshore winds rather than seeing a quick clean up.
For Boston, Cape Cod, the islands and coastal Maine, Friday night through to Sunday may well feel like a fight with the weather. Ferries could be delayed or cancelled. The fishing fleets may well be on the quay. Power crews will be on standby as saturated ground and wind-weakened trees will increase the risk of outages.
Mid-Atlantic: Flood Risk Builds
Further south the Mid-Atlantic coast shouldn’t be under any illusions about this system. The same offshore low can actually push water towards the coast and that will lead to higher tides and flooding in bays, inlets and tidal rivers.
The Jersey Shore and Long Island are specifically noted as areas where coastal flooding is possible over the weekend. Even in locations that won’t be hit by the worst of the wind there could be water ponding on roads at high tide, particularly around dawn and dusk when the tides are at their highest.
What Residents Should Do Now
- Secure any outdoor furniture, trash cans, decorations and any other loose items which the wind could turn into a projectile.
- Charge the phones, charge the backup batteries and charge the medical devices before Friday evening.
- Don’t drive through flooded roads at all. Turn around rather than risk the possibility of hidden damage or fast moving water.
- Get vehicles clear of the low lying coastal car parks prior to high tide.
- Keep your emergency supplies to hand (water, flashlights, medications, blankets, important documents etc) in a waterproof bag.
- Keep an eye on the official National Weather Service alerts as warnings and advisories can change very quickly as the storm develops.
The Bigger Picture
This isn’t currently being described as a hurricane threat. Atlantic tropical development prospects have been very limited and forecasters are instead looking at a non-tropical, nor’easter type coastal low as the primary concern. A nor’easter can be just as disruptive to coastal residents as a hurricane, especially if it gets stuck near the coast and causes water to pile up against the shore.
The East Coast is in for a truly dramatic few days with dark skies, roaring surf, soaked streets and winds that will rattle the windows from NJ all the way up to Maine. It may not be a named hurricane but it could still be a pretty significant event for the coast.
