Giant waves slam California coast
A series of storm systems, driven by persistent low pressure near Alaska, is churning waters to dangerous levels along the West Coast of the United States.
The focus of the punishment from massive waves is from southern Washington state through central California. The San Francisco Bay area is one region taking the brunt, with waves expected to reach 30 to 40 feet in height through Tuesday. It’s even been enough to postpone a surfing competition.
This event is huge, and truly affecting the whole West Coast. High surf warnings extend from north of the Oregon and Washington border to about a two-hour drive north of Los Angeles. High surf advisories or gale warnings stretch from the Canada to Mexico border.
“The dramatic wave heights are related to a consistent fetch of wind action that ... has origins up near Alaska,” writes Marshall Shepherd, professor of atmospheric sciences at the University of Georgia, for Forbes.
The cause of the widespread and life-threatening breakers along the West Coast is this massive upperlevel low pressure complex spinning around the Gulf of Alaska.
The gigantic gyre is blasting storm after storm at the West Coast. It’s also fostering ideal conditions for strong winds to blow over hundreds of miles of ocean, virtually unaltered, which piles up mammoth waves in the process.
The urgency highlights the unusual risk posed by this round of mega-swells.
Northern California, including the San Francisco Bay area, should end up with the worst of these pounding waves at the shoreline. The peak of the peak may be Monday, when waves in the 25 to 40 feet range could be common. Some could even exceed 50 feet, according to the Weather Service.
To the north of the Bay Area, wave heights in the 25- to 35-foot range are likely across the northern California coast and into Oregon. Heights slowly trail off to the north, but coastal zones north into Washington state face the risk of widespread strong winds as well as rainy conditions.
From Los Angeles and to the south, the wave action is enough for surf advisories with predicted heights between about 4 and 10 feet to the border with Mexico. Heading north along the coast from the Los Angeles area, wave heights climb to 15 to 25 feet across central portions of the California coast.
No major change in the pattern that is bringing this storminess ashore is expected in the short term, but the current intensity of the Alaskan low should wane in the days ahead. While large waves are likely for parts of the West Coast beyond Tuesday, the danger should be somewhat mitigated after that point.
the peak would probably be at the beginning of March, the authors found.
“That means that not only will there be less storage of snow, but also the time period over which we need to store water is longer,” Jones said. “The summer period is essentially growing.”
The new work is not the first to warn that the size of the Sierra Nevada snowpack will probably be drastically reduced in the future, or that the melting season could start earlier in the year.
However, the study is among the first to break down how global climate change will affect water flow in distinct regions of California.
“Scientists created climate models to understand global climate systems, but now people are asking what is going to happen in my local watershed,” Jones said.
It should also be noted that the authors don’t expect the march toward a smaller snowpack to be a straight line, but rather a winding road.
The winter of 2016-17 created one of the largest snowpacks in California history, loading reservoirs and rivers for months, even to the point of flooding some communities. Overall, the snowpack was 163 percent of average, which, when it melts, equals 46 inches of rain.