Officials are issuing warnings to beachgoers this weekend to beware of unusually strong "sneaker" waves that could sweep them into the ocean.

While the swells are only predicted to be 6 to 8 feet on Saturday and 8 to 10 feet on Sunday, the waves have extremely long periods between crests, as much as 25 seconds, compared to a normal 12 seconds.

That adds to the power of the waves and causes them to break higher, as much as 20 feet, and farther up on the beach than expected.

"There will be some dangerous waves," said Greg Probst, a state ranger at Salmon Creek. "It will look really flat and then some large swells will come in, sneaker waves, they call them. People get complacent and then some large waves come in."

Temperatures along the coast are forecast to be in the 60s and are expected to attract a lot of people to the coast, Probst said.

"We are telling park visitors: Don't go near the water. Don't turn your back to the waves," Probst said. "A lot of people will have dogs. Make sure the dogs are on a leash so they won't get washed in."

The warnings are in place until 4 p.m. Sunday, according to the U.S. Coast Guard.