A monster record-setting wave was recorded during a “bomb cyclone” less than 20 miles off the northern California coast last month, according to scientists at the Scripps Institute of Oceanography. At 74.4 feet high, it was the largest wave ever recorded by Scripps’ network of coastal buoys.
The wave was measured at a buoy off Cape Mendocino, in more than 1,000 feet of water. What was unusual was not only the size of this single wave, but also the size of average waves at the time. Scripps’ buoys measure average wave height every 30 minutes. The 74.4 wave came during a period when the average was a threatening 43 feet. The typical average this time of year, according to the Scripps’ scientists, is just 10 feet. These measurements were during the night of Nov. 26.
Waves of that height are not uncommon in the open ocean, but they are unusual so close to shore. “Waves of that size usually only occur far out to sea where the wind has been blowing across a big area,” James Behrens, manager of Scripps’ Coastal Information Program, told the SF Gate. “The only other station in the network that measures a wave this large is deployed 800 miles off the coast of Washington.”
These waves came when a bomb cyclone (a rapid drop in air pressure) hit the coasts of southern Oregon and northern California. The wind behind the cyclone churned up the ocean and built up wave height.
Scripps has half a dozen buoys off the California coast that measure wave height. The Cape Mendocino buoy was installed in 2004. For comparison, the World Meteorological Organization measured a record-breaking wave of 62.3 feet in the North Atlantic three years ago. Read more:
https://www.sfgate.com/weather/article/75-foot-tall-wave-largest-ever-California-14893034.php
