Celestial Lineup Triggers Heavy Weather : Syzygy: Odd Word That Spells Trouble

Syzygy, an exotic term for a celestial lineup of Earth, moon and sun, brought very high tides to North America for the new year, in time for a rampaging storm to make big trouble Friday for coastal New England.

Syzygy, pronounced SYZ-uh-jee, is a term for when the moon aligns directly opposite the Earth and sun or between the two bodies. Either alignment bulges the tides in some areas of the Earth.

Friday’s high tide of 11.7 feet above mean sea level was typical of that celestial bulging, but it was not a record for the area, said forecaster Tom McGuire of the National Weather Service. The average high is 9.5 feet, he said.

“Today, it’s mainly the contribution from the storm,” McGuire said Friday.

The high wind produces a storm surge that squeezes water above expected levels, he said. “It keeps the low tides from getting out so you start with more water,” he said. “That’s what happened in the blizzard of ’78.”

On Feb. 5, 1978, a two-day storm began that dumped 27 inches of snow on Boston was blamed for 29 deaths, destroyed 339 houses and heavily damaged 6,500 others. Property damage reached $300 million.

The height of the storm featured 100-m.p.h. winds, and storm tides grounded a tanker off Marblehead, north of Boston, washed away seawalls in Revere and washed away homes in Scituate.

In celestial terms, there are six alignments of sun, moon and Earth that contributed to higher than normal tides last week, according to the National Oceanic and Atmospheric Administration.

Researcher Bruce Parker said the most unusual factor is “a regression of the moon’s nodes.” That is when the orbital planes of earth, sun and moon align, which take place once in 18.6 years.

Other factors include:

- Annual winter perihelion, when the Earth is closest to the sun, which took place Saturday.

- Annual winter solstice, when the sun is furthest south of the Equator, which took place on Dec. 22.

- The monthly swing of the moon to its closest point to Earth, which took place on Tuesday.

- The northernmost or southernmost swing of the moon below the Equator twice a month, which also took place Tuesday.

- The lineup of moon and sun twice a month which produces the higher than normal spring tides, which took place Wednesday.