Nighttime gazers in for a treat

A “supermoon” rose over the Ravenel Bridge in 2011.

Good news for the Memorial Day weekend, the official kick-start to summer: You’ll have more beach to lie out on. And a huge moon to gaze upon at night.

Saturday’s moon will be the first of three “supermoons” expected this summer. That’s a full moon when the moon is near perigee, or its closest point to earth. Here’s what it means:

It will be wider.

At low tide Saturday afternoon, the surf will drop nearly a foot below normal depth. That translates to “a fair amount of real estate” down the slope of the sand, said Frank Alsheimer, National Weather Service meteorologist in Charleston.

Of course, it also means that high tide will swallow the beach. Today and Sunday will be nearly as high and low. Monday won’t be as dramatic.

The moon will seem gigantic on the horizon, rising or setting.

Today — Rises 7:59 p.m.; mostly clear skies.

Saturday — 9:05 p.m.; mostly clear skies.

Sunday — 10:07 p.m.; partly cloudy.

Tides will cover the marshes to the roadside. High tide Saturday is expected to rise within a tenth of a foot of the point where coastal flood advisories are issued. Tonight and Sunday are expected nearly as high.

“We’re certainly going to have to watch out for coastal flooding,” Alsheimer said.

At Charleston Harbor

Today — Highs 7:47 a.m., 8:26 p.m. Lows 1:55 a.m., 1:59 p.m.

Saturday — Highs 8:42 a.m., 9:19 p.m. Lows 2:47 a.m., 2:51 p.m.

Sunday — Highs 9:38 a.m., 10:13 p.m. Lows 3:39 a.m., 3:43 p.m.

This one is expected on June 23, when the full orb gets as close as it will this season. The third supermoon will come July 22.

Two Texas State University astronomers have speculated that a super supermoon might have led to the infamous sinking of the H.M.S. Titanic.

They said the January 1912 rise of the most extreme supermoon in 1,400 years would have spurred extreme tides that cracked icebergs from a Greenland glacier, then pushed them farther south than usual, into the shipping lanes where the Titanic smacked into one in April.

National Weather Service,, Texas State University,