PortandTerminal.com, December 9, 2019
SAN DIEGO, CA – The storm that hit the West Coast last week over Thanksgiving created some of the tallest waves ever recorded off the coast of California.
A massive 75-foot wave was recorded about 20 miles off the coast of Cape Mendocino in northern California, according to the University of California, San Diego’s Coastal Data Information Program (CDIP).
In the 15 years, the program has operated a station in that location, the significant wave height — or the average height of the tallest third of waves that occur over 30 minutes — typically doesn’t exceed 10 feet tall during the winter.
The 75-footer was the tallest of the waves recorded in that period, which averaged around 43 feet tall. Still, that’s “definitely unusual” for this time of year, program manager James Behrens told CNN.
“These kinds of really large waves are usually only detected way out in the middle of the ocean when winds are being generated,” he said.
The program’s buoys had only measured taller waves at one other station, located in the remote North Pacific Ocean where extreme waves are expected to form on occasion, he said. Troy Nicolini, meteorologist in charge at NOAA’s National Weather Service, explained that the bomb cyclone brought a dynamic fetch, an event when strong winds move in the same direction and speed as the waves it’s generating. He compared it to pushing a child on the swing as they move — maintaining the push instead of laying off when they’re in the air will shove the kid off the swing. Similarly, the storm maintained its grip on the waves and shoved it all the way up to the beach, he said.