Residents and visitors heading to Bay Area beaches are being warned to stay out of the water, and to stay off rocks and jetties near the water, amid a high risk for rip currents, sneaker waves, and dangerous high surf starting starting Thursday.

Waves breaking at 20 and 30 feet high may be great news for experienced big-wave surfers at Mavericks. But for most everyone these conditions present serious dangers on Bay Area beaches — conditions that, in most years, claim a few unsuspecting lives.

The National Weather Service has issued a high surf advisory starting 10 am Thursday and going through 4 pm Sunday, covering the entire Pacific coastline of the region, including San Francisco.

Meanwhile, the San Francisco Fire Department has also issued a warning about the beach conditions, saying "Swimming is strongly discouraged at Ocean Beach" due to the potential for rip currents. And while they're saying that "wading to your knees is allowed," we're saying you shouldn't be doing that either, as December and January annually bring tragic stories of people visiting beaches around the Bay Area, wading in shallow water, and getting knocked down and swept out to sea by a sneaker wave.

Also, everyone should be staying off rocks and jetties where they might want to take selfies, as these are also places where people get swept out to seek by unexpected or unseen waves.

The SFFD is also encouraging dog owners at the beach to keep dogs leashed and keep them out of the water, and to not go in after them if the dog suddenly gets swept out. "Most dogs will get out of the water, only to watch their handler [need to] get rescued," the department says.

Surfing is also discouraged at Ocean Beach the next few days. Surfers have been heading to Mavericks near Half Moon Bay to surf the notoriously huge break there, however these are experienced big-wave surfers aware of the risks of these powerful waves.

Stay safe out there! And if you want to go see the ocean this weekend, do so from a safe distance!

Photo: Jeremy Bishop