Skywatchers are calling it the “trifecta” — a three-in-one celestial event that hasn’t happened in more than 150 years.

Before dawn Wednesday, if the clouds cooperate, Hawaii will witness an hours-long total lunar eclipse. The nickname for that is a blood moon because the surface will appear red.

The moon will be near perigee, its closest distance to Earth, making it a so-called supermoon because it is bigger than usual — by 14 percent, according to NASA.

This also will be the second full moon of the month, called a blue moon, as in “once in a blue moon.”

So we’re talking about a super blue blood moon.

Some wits say that makes it a super purple moon.

Whatever you call it, it will be a once-in-a-lifetime opportunity for early risers and night owls.

In Hawaii the phenomenon will occur as the moon descends in the west, so any vantage point with a clear view in that direction will work. Forecasters say Maui and Hawaii island will have the best chance of clear skies.

“Weather permitting, the West Coast, Alaska and Hawaii will have a spectacular view of totality from start to finish,” said Gordon Johnston, program executive and lunar blogger at NASA headquarters in Washington, on the agency’s website. “Set your alarm early and go out and take a look.”

The edge of the moon will enter Earth’s outer shadow, or penumbra, at 12:51 a.m.

At 1:48 a.m. the partial eclipse will begin as the moon edges into the darker, inner shadow, or umbra.

Totality begins at 2:51 a.m. and will last until 4:07 a.m.

The partial eclipse will end at 5:11 a.m.

Unfortunately, the National Weather Service predicts an 80 percent chance of rain and possible thunderstorms for Wednesday on Oahu.

On Tuesday, southerly winds will increase ahead of an approaching front. The front is expected to reach Kauai on Tuesday night, then stall across Oahu and Molokai on Wednesday, the agency said.

What time the front will hit Oahu on Wednesday is uncertain.

“It looks like it’s going to be pretty cloudy,” weather service meteorologist Robert Bohlin said Sunday. “There might be some breaks but conditions don’t look good. It’s going to be challenging for Oahu. There is a better chance on Maui and the Big Island. The farther east you go, the better the chances.”

He added, “It looks like there are going to be some higher clouds, too. It’s just not looking good.”

The next lunar eclipse visible in the United States will be on Jan. 21, and will be a supermoon but not a blue moon.

The distance to the moon varies over the course of its orbit, from 221,500 to 252,700 miles. It is currently about 223,000 miles away, according to timeanddate.com.

That website also has an interactive animation of the eclipse, available at www.timeanddate.com/eclipse/in/usa/honolulu.

When the moon is in Earth’s umbra, all direct sunlight is blocked, but some light curves around Earth, bent by the atmosphere, bathing the moon in a reddish or orange glow. Thus the term blood moon.

The last time there was a super blue blood moon over North America was on March 31, 1866. Other parts of the world experienced a blue blood moon in December 1982.