Weather Watch

Polar vortex brought brutal cold to Texas. Could that happen in California?

PG&E meteorologist John LIndsey took this photo of snow on the San Rafael Mountains.
PG&E meteorologist John LIndsey took this photo of snow on the San Rafael Mountains.

Last week, brutally frigid air settled over a massive stretch of the United States that left millions without electricity, heat and water in Texas. I never expected to see snow-covered beaches in Galveston.

This historical story of cold may have started weeks ago, and thousands of miles away, and here is why.

In January 2020, a dramatic spike in temperatures occurred in the stratospheric miles above the North Pole. This is referred to as “sudden stratospheric warming.”

This condition caused the polar vortex to slow down and transform from a fast-moving circular orbit over the Arctic to an unstable and extremely wavy jet stream that allowed frigid air from the North Pole to move southward through the midsection of the country.

Is climate change causing these freezing temperatures?

A hypothesis that continues to gain interest was put forth several years ago by Dr. Jennifer Francis at Woods Hole Research Center. She hypothesizes that arctic amplification — meaning that the Arctic is warming faster than the rest of the Earth — will increase jet stream waves’ amplitude.

In other words, the upper-level winds are more likely to travel in a more north-to-south pattern. The polar jet stream, or, polar vortex, often forms the border between the frigid air to the north and the warmer air to the south.

As a rule of thumb, the higher the temperature differential between these two air masses, the faster the upper-level winds will blow. The quicker the jet stream, the more direct route it takes.

The slower the jet stream, the more likely it will tend to change its direction and bring frosty air southward into historically mild parts of the county.

Could the same pattern happen in California?

Cold weather event hits SLO County

In late December 1990, a strong southerly flowing jet stream moved a cold Arctic air mass from western Canada, the so-called Yukon Express, down the West Coast.

There were reports of snowflakes in Paso Robles, San Luis Obispo and even Pismo Beach and Nipomo on the night of Dec. 20, 1990, with overnight lows falling to the low 20s on the north side of the Cuesta Grade.

By Dec. 22, 1990, the winds at Diablo Canyon Power Plant shifted out of the north-northeast, and the temperature nearly hit the freezing point for the first time since 1976 when Diablo Canyon first started keeping weather records.

Atascadero fell to a bone-chilling 4 degrees Fahrenheit while Templeton dropped to a numbing 9 degrees. The Paso Robles Airport reported an all-time low of 8 degrees, and San Luis Obispo dropped to 17 degrees.

The average temperature in Santa Maria was 38 degrees over a 48-hour period. Gary Ryan, a meteorologist with the National Weather Service in Santa Maria, confirmed these record-breaking low temperatures on Dec. 22 and Dec. 23.

The region’s avocado crop was hard hit, and numerous water pipes burst.

Much like the tradesmen in Texas today, Central Coast plumbers were kept busy for days afterward repairing pipes and fixtures.

Many local hardware stores were completely sold out of plastic and copper pipe and anything else to do with plumbing.

Freezing winds blew through the Salinas Valley and killed or severely damaged many eucalyptus trees along Highway 101.

At the time, I was a reservist stationed at Naval Air Station Alameda with an H-3 Sea King helicopter squadron (HS-85).

On Dec. 21, we took off for a flight near the Golden Gate Bridge. It was one of the rare times we had to turn on the helicopter’s heater while flying around the Bay Area. A bitterly cold and cutting north wind blew across the Marin Headlands on the Golden Gate’s north side toward San Francisco.

The sky was overcast, which gave an ash-gray hue to the surrounding mountains. It was surreal; the Golden Gate National Recreation Area felt and looked more like the rocky coast of Nova Scotia in winter.

I previously couldn’t remember when there weren’t at least a few people walking across the bridge. On that day, we didn’t see anybody on that massive orange span.

This was considered a once-in-100-year event.

As the Earth warms and the rate of climate change increases, many atmospheric scientists predict these cold- weather events will occur more frequently.

By coincidence, a few of the longer-range charts are advertising a deep trough of low pressure developing over the West Coast during the second week of March that could lead to freezing temperatures, much-needed rain and low-elevation snow throughout the Golden State.

Remember, these are long-range models and will probably change.

PG&E is launching its EV Fast Charge program to help accelerate electric vehicle adoption in California. For more on PG’s EV Fast Charge program, visit pge.com/evfastcharge.

John Lindsey’s column is special to The Tribune. He is PG&E’s Diablo Canyon marine meteorologist and a media relations representative. Email him at pgeweather@pge.com or follow him on Twitter: @PGE_John.

This story was originally published February 23, 2021 at 5:05 AM.

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