2023 SWOF – Breakout winter, big waves, big rains team up

The 2022-23 winter Atmospheric Rivers (formerly known as the Pineapple Express) stretched from southwest of Hawaii to California. Image Source: NASA WorldView

by Rick Dickert

Not since the 1988 storm surf that blew holes in the Redondo Beach Breakwall, and blew out windows in the Portofino Hotel has the South Bay seen surf as large as this past winter’s.

The fact that the 2022-23 winter also experienced a record amount of rain is not a coincidence. 

The preceding years of drought and small surf resulted from an  “R3,” or the Ridiculously Resilient Ridge that parked itself along the West Coast of North America.

It certainly was ridiculously resilient. It maintained its position and strength for several wet seasons, blocking Pacific storms from reaching California. The high pressure system produced sinking air, which inhibited condensation, cloud cover and precipitation. 

The extended drought applied to the surf as well. Last winter, the annual South Bay Boardriders annual Big Wave Challenge had to be canceled because there were no big waves. 

This winter, the high pressure system, which has been a dominant feature of our weather for the past several years, finally broke down and allowed the jet stream (storm track) to penetrate California.

The series of strong, low pressure systems stretched from southwest of Hawaii to the California coast, bringing with them much needed rain and mountain snow. It also brought big surf. 

Low pressure systems produce rising air and rain, and high winds.

Waves are formed by high wind blowing across the open ocean. Low pressure systems spinning thousands of miles off our coast generate winds of 60 knots or higher. Near the core of these deep (strong) lows and hurricane force winds, the high seas are chaotic. But as the waves fans out from the Pacific storms they become organized swells.

While this past winter’s storms were developing over our world’s largest and deepest ocean, some were positioned far enough south to tap into tropical moisture. This formed the ARs (atmospheric rivers, formerly known as the Pineapple Express) that inundated our state with torrential rain, snow, wind and surf. 

The warmer the atmosphere, the more moisture it can hold, leading to the record amounts of precipitation that fell across our state. 

These ARs with their plumes of concentrated moisture are the largest rivers on our planet. Between Dec and Jan, 9 separate atmospheric rivers dumped 32 trillion gallons of water on California. 

(It’s important to note that not all the large swells this winter were generated by ARs. Some came from powerful storms in the Gulf of Alaska.) 

In addition to producing big surf, the persistent, west-northwest wind, especially in March resulted in a lot of upwelling of deep cold water, which is why near shore water temperatures dropped to full wetsuit levels. As of April 7, the Santa Monica Bay Buoy was reporting a well below average reading of just 55 degrees. 

Winter 2022-23 by the numbers  

Los Angeles Water Year Total (October 22 through April 1): 27.42 inches. This is almost double the entire year average for Los Angeles, of 14.25 inches. Los Angeles has been wetter this year than Seattle, which had 22.65 inches, through April 1).

Sierra Nevada Snow Pack: The final snowpack measurement showed the water equivalent at 221 percent of the historic average, the most since record keeping began.

Too much of a good thing

Our planet has warmed 2 degrees Farenheit over the last century. Climate scientists predict this warming trend will continue, fueling our atmosphere with additional heat. Added warmth means increased moisture holding capacity for the air over our oceans, which cover 70 percent of Earth. Experts believe this will produce wetter and stronger atmospheric rivers and likely more overhead days at 16th Street.

Rick Dickert is a FOX 11 Certified Broadcast Meteorologist. He is also a  LAX Aviation Weather Observer, and a Cooperative National Weather Service Observer for Redondo Beach. ER

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