Summer turning up in blobs

Cannonball jellies have moved in along the coast. That means beach weather can’t be far behind.

Yep, beach weather is on its way. You can tell by those globs of blob in the tide.

Cannonball jellies are turning up big time along the beaches, pushed in from the Gulf Stream with washes of warmer water. They’re the “Open for Swimming” sign that the surf is approaching that magic room-temperature zone a lot of people find plunge-able on a hot day.

“They let us know that sea surface temps have started to reach upper 60s. Many times they let us know before our most sophisticated satellites can detect the slightest difference of just a few degrees water surface temperature change,” said meteorologist Shea Gibson of WeatherFlow.

For Gibson, a wind surfer who gears some forecasts to the sport, the jellies mean something more. They’re also a sign that sea and land winds are “coupling,” weaving into more predictable patterns that bring stronger, warmer southerly sea breezes for the surfers.

“In other words, it’s a turning point for our warmer weather,” he said.

The cannonballs will be around in droves until sea temperatures reach the 80s — out of their comfort zone.

“They’ll be here through September,” said Shannon Howard, South Carolina Aquarium senior biologist and a Folly Beach Turtle Watch volunteer.

Cannonballs can sting, despite the “harmless” rep they have cultivated over the years, but the sting is too mild for people to notice. They have arrived with comb jellies, smaller creatures that look like they’re encased in a bubble and refract light in fascinating rainbow streams. They don’t sting.

In fact, spring might be the safest time of the year to swim as far as jellyfish stings. Lion’s manes, which resemble cannonballs but have a vicious sting, tend to be cold water critters that move on out as waters warm.

Sea nettles, viciously stinging jellies that somewhat resemble cannonballs but have trailing tentacles, don’t move in until the waters really warm. They’re heaviest in mid-summer. So are sea wasps, or box jellies, another notorious stinger with long, trailing tentacles.

And Portuguese man o’wars, the alluring blue jellies with “sails” and screamingly painful stings, tend to wash in only with strong winds out of the east. A lot of sargassum, or seaweed, washing up is a sign there might be man o’wars around, Howard said.

Prevailing spring winds here come from the other directions. So go on. Take a plunge. It’s summer, or close enough.

Reach Bo Petersen at 843-937-5744, @bopete on twitter or Bo Petersen Reporting on Facebook.