SAN FRANCISCO (AP) — Officials warn that potentially dangerous waves are expected along the coast in the San Francisco Bay Area.

The San Francisco Chronicle reports Monday that “sneaker waves” that can suddenly surge to 3-4 feet are expected Monday afternoon.

The National Weather Service issued the warning and urged people to stay back from the waves.

People should also be careful not to turn their backs to the sea. A boy was swept away and drowned earlier this year when a powerful wave dragged him into the ocean at Cowell Ranch State Beach in San Mateo County.