Предупреждения, Сан Франциско

High Surf Advisory issued December 21 at 12:47AM PST until December 22 at 4:00PM PST by NWS San Francisco CA * WHAT...Expect large westerly swell with breaking waves of 20 to 26 feet, including breakers near 30 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...From 6 AM this morning to 4 PM PST Sunday. * IMPACTS...Dangerous swimming and surfing conditions and localized beach erosion. 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. Inexperienced swimmers should remain out of the water due to dangerous surf conditions.