High Surf Advisory issued December 22 at 1:14AM PST until December 22 at 4:00PM PST by NWS San Francisco CA

* WHAT…For the High Surf Advisory, large breaking waves of 20 to
26 feet, including breakers near 30 feet at favored spots such
as Mavericks. For the High Surf Warning, dangerously large
breaking waves of 30 to 35 feet, including breakers up to 40
feet at favored spots such as Mavericks.

* WHERE…San Francisco, Coastal North Bay Including Point Reyes
National Seashore, San Francisco Peninsula Coast, Northern
Monterey Bay and Southern Monterey Bay and Big Sur Coast.

* WHEN…For the High Surf Advisory, until 4 PM PST this
afternoon. For the High Surf Warning, from 4 PM this afternoon
to noon PST Tuesday.

* IMPACTS…Life-threatening swimming and surfing conditions and
significant beach erosion can be expected. Large waves can sweep
across the beach without warning, pulling people into the sea
from rocks, jetties and beaches. Sudden immersion in cold water
can result in cold water shock even for the most experienced
swimmers. Cold water shock can result in dramatic changes in
breathing, heart rate and blood pressure, greatly increasing the
risk of drowning in rough open waters.