The National Weather Service has issued a warning about dangerous conditions on the Northern California Coast. According to the San Francisco Chronicle, waves up to 18 feet high are forecast through Tuesday morning. Sneaker waves (large waves that come up unexpectedly) and dangerous rip currents (strong surface currents that pull quickly away from the shore) are expected.
Roberta Gonzales, a meteorologist at KPIX, told a Chronicle reporter swimmers should "exercise extreme caution." The National Weather Service included the tried-and-true warning "never turn your back on the ocean" in its report.
The report says that waves will be significantly higher in the open ocean, where swells as high as 54 feet could be possible and gale force winds of 46 miles per hour are forecast.