Experts explain why tide swings have been unusually high

Some East End fishermen and captains have noticed abnormally high tides this summer, but what’s puzzled some scientists is that they were not alone. Tides have been running unusually high from Maine to the east coast of Florida, according to the National Oceanic and Atmospheric Administration.

“The geographic scope of it is something we have not noticed before—from New England to Florida,” said Richard Edwing, the deputy director for the NOAA Tides and Currents department, on the phone from his office in Silver Spring, Maryland.

In early June, his office started getting calls from people up and down the East Coast who said the NOAA tide predictions on its website were wildly inaccurate. After investigating, Mr. Edwing said scientists saw that water levels were elevated by about a foot along the northern and southern states and up to two feet above normal in the mid-Atlantic states at the end of June.

Tides running 1.2 feet higher than normal was the biggest anomaly that NOAA recorded off Montauk, Mr. Edwing said.

“The tides were actually at one point even with the top of the docks,” said Captain Scott Schafer of the charter fishing boat 50-50 in the Montauk Marine Basin. “The boat floats even with the water and you had to climb up to get in. It was pretty wild.”

The phenomenon has now abated here in the North, minus the variations from recent storms like the unusual gale last Thursday night.

Mr. Edwing said that from basic research his NOAA department has done so far, there seemed to be two contributing factors occurring simultaneously to cause the anomalous high tide along the entire East Coast. First, a weather pattern that typically happens in the Northeast in the fall—sustained easterly winds blowing to the southwest, pushing water to the coast—happened in June.

Second, the Gulf Stream seemed to slow down. “I can’t tell you why, but it slowed down,” said Mr. Edwing.

Usually where the Gulf Stream flows, the surface elevation of the ocean is higher because it sucks up water from between the coast and the stream. But when the Gulf Stream slows down, it needs less water.

“That’s what was happening along the Southeast coast, it was pulling less water away from coast,” Mr. Edwing said. “But toward the northern end, it was more the wind.” The mid-Atlantic states were hit with both factors.

To top it off, there was a perigean tide in June, which occurs when the moon is closest to the Earth, causing the tides to be their highest and lowest because the moon’s gravitational pull is at its strongest.

Mr. Edwing said there was a good chance the combination of factors causing the high waters could be a part of normal variability. “There is nothing that suggests that it’s a product of global warming,” Mr. Edwing said. He said NOAA scientists were working on a more detailed report on the possible causes for the unusual winds in June and for the slowing Gulf Stream. They will also continue to monitor the tides much closer.

Local captains and fishermen have been murmuring about the extreme high tides, but those interviewed didn’t think it was anything that out of the ordinary.

“High tides have been above normal,” said East Hampton Town Harbormaster Ed Michels. “I noticed that water was up to levels I haven’t seen in a while. But they’ve gone back to normal.”

Town Councilman Brad Loewen, a former commercial fisherman and current member of the East Hampton Baymen’s Association, said that “everybody had noticed the tides were abnormal.”

“It affects the ability for us to fish in the normal way because you have extreme movement of water,” Mr. Loewen said. “The gill nets get dirty faster because there’s a lot more grass floating in the current. You have to readjust the height of the pound net because the fish would just swim over it.”

Out in Montauk, there was no need for NOAA’s official conclusion for locals to know what had caused the high waters.

“We’ve had a lot of easterly winds which put the water back into the harbor and bays, which could be part of it,” said Captain Schafer.

“We’re attributing that to all the east wind,” said Paul Apostolides, the owner of Paulie’s Tackle in Montauk. “Not too many people are complaining about it. The sand beaches seemed to get beat up pretty good this year. The east wind pushes a lot of water up this way. That’s just a guess, we just stand around talking about it all the time.”