By Kerry Anderson

A rogue wave caught onlookers off guard on Thursday afternoon in Ventura, California sending 8 to the hospital with moderate to minor wounds. People had gathered at the beachfront to view the large surf when the wave overtopped the beachwall sending seawater into the nearby streets.

Courtesy: The Oregonian and Ventura County Fire Department

A rogue wave is a wave that is more than twice the size of the surrounding waves and may come from a different direction. These can develop as waves from different wind patterns encounter one another. As the waves will converge on one another if the two waves are of similar height and length they can sync and amplify into one much larger wave.

This week’s storm pattern in the Northern Pacific has two very large storm systems (purple bands in map below) that are in line with one another. They are both very deep Low-pressure areas with a lot of energy and they have been producing a long period of WNW winds. This has driven a lot of wave energy directly toward Southern California.

The high waves will continue into early next week until these storms have passed. The GFS model(below) is predicting the next period of high waves to move toward the California coast on Saturday morning as the first low moves toward the coast. (dark green area on the map).

Winds are not the only reason why the waves have been so high this week. The other factor is the tides. Tuesday was a full moon. Tides are highest during full and new moons due to the additive gravitational pull of the sun and the moon when they are aligned. So high tides are higher and low tides are lower.

As the next round of wave energy hits the Southern California shores at high tide the National Weather Service is warning that waves may be up to 20 feet high.