In early 2014 several winter (extra tropical) storms developed off the western coast of the U.S. In the case of the storm featured in the video below, the extratropical cyclone had already developed and then merged with a cold front or “atmospheric river” in February of 2014. Another event developed a strong rotation later in February and early March. This storm was named Titan. Collectively, these atmospheric river producing events helped to form large coastal swells and brought much-needed rain to California. The state had been suffering from significant drought conditions for more than 3 years.
Please watch the following video (1:06) entitled "Animation of extratropical cyclone merging with atmospheric river off California." (There is no narration.)
Please watch the following video (0:57) entitled "2/28/14-3/1/14 West Coast Extratropical Cyclone Water Vapor Satellite Loop." (There is no audio.)
The National Weather Service reported that more rain fell in a few hours than had fallen in eight months as a result of just one of these storms. Due to the relatively steep terrain of the region, and because of the extensive drought, as much needed as the rain was, numerous landslides resulted and coastal erosion at the base of several sections of the coastal highway were undermined or buried. In some areas, roads were closed and people were evacuated. So, although the storms were not as large in scale as most tropical storms, they definitely impacted coastal regions in many of the same ways.
Below, a home video taken in 2008 at Marina State Beach, just north of Monterey California and south of Salinas River National Wildlife Refuge shows massive waves some 30’ high (video (1:53) entitled "Giant Pacific Wave Storm January 5th, 2008). The video illustrates the power of waves as they interact with the shoreline.
Although the winds don’t appear to be too intense, significant wave run-up is shown, and you can easily see how the swells produce extensive coastal scour and erosion along the shoreline. In the months following, portions of California experienced additional storm activity. Large waves, some in excess of 15 feet, pounded the shoreline up and down the coast. High winds, some gusts as high as 55 mph, were measured and significant accumulations of snow were dumped at higher elevations, High Surf, Wild Winds Pound Southern California CBS Los Angeles).