About
Each year, in Northern California, someone loses their life to a “sneaker wave.”1 The wave may have snuck up on that person, but it came from thousands of miles away and the swell that brought it was tracked for days before it arrived.
We believe that, armed with good information about conditions, beach goers can make good decisions while enjoying the magnificence of the California Coast.
Wave height, period, direction, water temperature, air temperature and wind are read from three NOAA National Data Buoy Center stations: 46012 Half Moon Bay, 46026 San Francisco Bar, and 46013 Bodega Bay. Readings refresh every thirty minutes.
Buoy readings are taken offshore. Conditions at the water can differ from what the buoy reports.
The advisory shown on each beach page is read from the National Weather Service active alerts feed for that stretch of coast: CAZ529 San Mateo, CAZ006 San Francisco, CAZ507 Marin, CAZ112 Sonoma. This site displays the advisory as issued and does not calculate it.
Hazards listed on each beach page are drawn from California State Parks Ocean Safety, the National Park Service, the joint NPS, SF Fire Department and NOAA coastal safety advisory, and National Weather Service beach hazards guidance. Each hazard card carries its own source.
- 1 García-Medina, G., Özkan-Haller, H.T., Ruggiero, P., Holman, R.A., and Nicolini, T. (2018). Analysis and catalogue of sneaker waves in the US Pacific Northwest between 2005 and 2017. Natural Hazards, 94(2). The study attributed 29 fatalities to sneaker waves over those twelve years, 15 in Oregon and 14 in northern California. Citation record ↗ · doi:10.1007/s11069-018-3403-z ↩ back