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Super moon, king tides to return
On Nov. 14, the moon will make its closest pass to Earth since January 1948. It is going to appear about 14 percent bigger than normal. (John Tlumacki/Globe Staff/file)
By Olivia Quintana
Globe Correspondent

This month, the moon will make its closest pass to Earth since January 1948.

The “super moon’’ on Nov. 14 is going to appear about 14 percent bigger than a normal full moon, according to Quinn Sykes, the manager of Boston University’s Judson B. Coit Observatory.

“It will be a little bigger and a little brighter, and it will be cool to look at it,’’ Sykes said.

Sykes said the moon will seem biggest when it is on the horizon, which will be right after sunset at about 4:30 p.m. that day.

A super moon happens when the moon is close to the Earth during its fullest stage, Sykes said.

“It has to do with the orbit of the moon around the Earth, because it’s not a circle. It’s an oval, so it has periods when it’s closer and when it’s a little farther away,’’ he said.

“That point of closeness has to be during a full moon. It can get close at a different moon phase, but when it happens during the full moon, then it’s a super moon,’’ Sykes added.

The full moon will also bring the return of so-called king tides — higher-than-normal tides.

“You have the alignment of the moon with the sun, so you have a double pull of gravity to the Earth itself,’’ said Benjamin Sipprell, a meteorologist for the National Weather Service said. “That creates those king tides.’’

Sipprell said the peak tides are expected to be between 12.4 and 12.5 feet high at noon on Nov. 15. However, with wind and wave activity, the actual tides could be higher.

The king tides that Boston Harbor saw in October were predicted to be 12.2 to 12.3 feet high. In reality though, they ended up being about 12.8 feet high.

“A little bit of wind and wave action invoked about a half-foot more than what was predicted,’’ Sipprell said. “If you were to take those conditions from October that gave that extra half a foot of tide and applied them to November, you could get a 13 foot tide, which would be significant for the Boston coastline.’’

However, he said it’s difficult to predict what will actually happen with the high tides.

“It all depends on the weather conditions,’’ Sipprell said.

Olivia Quintana can be reached at olivia.quintana@globe.com. Follow her on Twitter @oliviasquintana.