'Don't go to the beach': Waves up to 6 stories forecast for Bay Area beaches

Pro surfer Francisco Porcella surfing Mavericks off Half Moon Bay, Calif., on Wed. Nov. 28, 2018. Keeping clicking to see images from the 2016 Mavericks surf contest. Pro surfer Francisco Porcella surfing Mavericks off Half Moon Bay, Calif., on Wed. Nov. 28, 2018. Keeping clicking to see images from the 2016 Mavericks surf contest. Photo: Ben Schutzer / RunAmuck Photography Photo: Ben Schutzer / RunAmuck Photography Image 1 of / 72 Caption Close 'Don't go to the beach': Waves up to 6 stories forecast for Bay Area beaches 1 / 72 Back to Gallery

Massive mountainous waves, in some cases up to six stories tall, are in the forecast for San Francisco Bay Area beaches.

A fierce storm brewing in the northwest Pacific off the Aleutian Islands is moving toward the West Coast and forecast to deliver a turbulent west-northwest swell Sunday through Tuesday.

The surf's arrival is still three days off, so meteorologists are hesitant to quantify where this event falls among others. But some are speculating is this is going to be big — possibly the biggest in years — National Weather Service forecaster Brian Garcia wants to get the message out: "Don't go to the beach. Don't step on the sand. Stay on the sidewalk."

This warning, Garcia says, is especially important for San Franciscans. Their local beach, Ocean Beach, is a popular hang-out spot and breakers here are forecast to reach four-stories tall, with some isolated sets maybe even reaching 50 to 60 feet.

"We'll have long periods of time where there's very little run up up the beach, and then there will be waves that run up far and can put people into chest to waist deep water pretty quick," said Garcia. "You can go into cold water paralysis and drown."

The big swell starts Sunday at 8 a.m. when small yet energetic waves with long periods of time between them — known as "forerunners"— roll into beaches. Garcia is most concerned about beach safety at this time, as the ocean will appear safe and the waves will have long periods of time between them.

The wave height will grow throughout the day Sunday, peaking Sunday night into Monday morning. The largest waves will be at west-to-northwest-facing beaches, such as Ocean Beach in S.F., Montara State Beach near Half Moon Bay and Marina State Beach near Monterey.

"At well-exposed breaks, it's probably going to be in the 30 to 40 foot range," said Garcia. "There could be moments that go 50 to 60, but that's not the norm throughout the day. We're talking Ocean Beach, Mavericks, the wave magnets."

ALSO: High surf at Mavericks: Contest could come early next week

The monsters with 60-foot faces are most likely at famed big-wave mecca, Mavericks Beach off the coast of Half Moon Bay. The World Surf League is keeping an eye on the spot to determine whether next week might be the time to hold the annual contest known as the Mavericks Challenge.

Mavericks requires the perfect combination of big swell, low tide and just the winds that aren't too strong to be surfable.

"On Monday, I can almost guarantee there will be some people out there surfing," said Garcia. "I'm not sure it's going to be a big enough window with a big enough swell to hold it for the contest, but usually these big swells last longer than models indicate. Right now, it looks like winds will be light."

While professional surfers from around the world are making plans to head to the West Coast for the monster break, there are also many local surfers who enjoy the challenge of Mavericks and hope to catch some epic waves.

"This is the biggest run of swell I've seen in my lifetime," said Jake Tellkamp, 26, a student at San Francisco State University.