A waterspout seen near Fenwick Island in the ACE Basin on Tuesday might have been the same funnel spotted near Hunting Island. Provided by Syd Shuler 

Better keep your eyes peeled at the beach and on the water. We're in the "sweet spot" for waterspouts to form, forecasters say.

At least one, and maybe two, waterspouts spun up near Hunting Island in Colleton County south of Charleston on Tuesday after a large one came ashore Monday to the astonishment of bathers in Myrtle Beach.

Waterspouts are funnels of wind like tornadoes over water. In storms, they spin down from clouds and can be as powerful as tornadoes, with winds more than 100 mph, according to the National Oceanic and Atmospheric Administration.

In fairer weather, the right combination of moisture in the air and light winds tend to stir the funnels, said meteorologist Emily McGraw with the National Weather Service office in Charleston.

"Typically now is the prime time in the summer for waterspouts," she said.

The spout Monday came ashore at Myrtle Beach at 9th Avenue North, near the town's seaside Ferris wheel, tossing umbrellas and beach chairs into the air as beachgoers gaped. The funnel's wind was estimated at 60 mph, according to the National Weather Service in Wilmington.

That was in the early afternoon, which was unusual.

"Typically, water spouts are common along the South Carolina coast in the mornings when we have offshore winds meeting the sea breeze front, which slowly creeps towards the coast with an onshore flow," said meteorologist Shea Gibson, a Charleston-based forecaster with the WeatherFlow company.

As the sun heats up, those conditions tend to wane. 

Winds in the morning on Wednesday should be too strong for waterspouts to form, but they could, McGraw said.

"It's certainly a possibility," she said.

Reach Bo Petersen Reporter at Facebook, @bopete on Twitter or 1-843-937-5744.

Science and environment reporter. Author of Washing Our Hands in the Clouds.