On Saturday, as a powerful winter storm headed toward the Bay Area, San Francisco residents received a tornado warning from the National Weather Service. But no tornado touched down. Yet 50 miles to the south, Scotts Valley, in Santa Cruz County, didn’t receive a tornado warning and a tornado did hit the community, flipping seven cars, breaking trees and causing five injuries.

What happened?

Despite computer models, radar systems and modern satellites, the event highlighted how predicting the precise location of extreme weather events still can be difficult, experts said Monday.

Officials from the National Weather Service said conditions in San Francisco and Santa Cruz County were very similar Saturday. The storms came from the same system. Radar images showed similar patterns. And the winds turned out to be similar — with gusts to 80 mph toppling trees at Golden Gate Park in San Francisco and the tornado in Scotts Valley later in the day reaching 90 mph.

The tornado never touched down in San Francisco. But the conditions in the atmosphere with wind speed and direction were right, said Brian Garcia, warning coordination meteorologist for National Weather Service in the Bay Area.

“San Francisco got lucky,” he said.

The National Weather Service issued a tornado warning for San Francisco at 5:51 a.m. Saturday, the first in its history.

Tornadoes are rare but not unheard of in California. Since 1950, there have been 482, according to federal records. The Central Valley receives more than other areas. The Bay Area’s most recent was in 2016, when a waterspout appeared during a storm over Lake Berryessa in Napa County. The East Bay had one in Brentwood in 2010. Gilroy had one in 2007.

Santa Cruz County has had 7 in the past 75 years: The most recent occurred Jan. 6, 2019, when one tore much of the roof off the Dolphin Restaurant at the end of the Santa Cruz Wharf before dissipating. Often they form just a few miles offshore as waterspouts, giving little warning.

“These things have very short life spans,” said Jan Null, a meteorologist with Golden Gate Weather Services in Half Moon Bay. “It’s not like you can track it for hours. That makes them very tough to warn people about.”

Tornadoes are less likely to occur in mountainous areas like Santa Cruz County, than in flat areas, because mountains often break up the swirling wind patterns. Given that, and seeing no tornado touch down in San Francisco, Garcia said, the National Weather Service issued a severe thunderstorm warning for Scotts Valley and much of Santa Cruz County instead of a tornado warning at 1:25 p.m. as the storm’s impacts moved south.

“A severe thunderstorm warning and a tornado warning both have similar calls to action,” he said. “Seek shelter immediately. Severe thunderstorms can have winds as strong as tornadoes. The difference is they are in a straight line rather than spinning.”

Another difference is the type of notification the public receives.

Under federal rules established in 2012, the National Weather Service sends alerts to cell phones of people living in the affected area when there are tornado warnings, along with other threats like hurricanes or tsunamis.

But in 2021 after getting complaints of too many cell phone alerts from residents in the Midwest where such storms are more common, the agency decided to only send them for the most extreme types of severe thunderstorms. There are three levels, and the agency’s meteorologists determined that Saturday’s  storm looked like the lowest of the three.

As a result, 1 million people in San Francisco had an alert from the federal Weather Emergency Alert service buzz their phones Saturday morning. Nobody in Scotts Valley did, although some people reported phone warnings which likely came from weather apps and other programs.

“We had a front-row seat,” said Denise Fritsch, a saleswoman at Home by Zinnia’s decor store on Mount Hermon Road next to Target, where the damage was worst. “Our doors were sucked open, then slammed shut really quick. The wreaths went sailing.”

A few blocks away, the funnel cloud hit her husband’s car, breaking a window, mirror and tail light but leaving him unhurt, Fritsch said.

“If anybody knew it was coming they should’ve warned us,” she said, “but I don’t know if anyone knew what was coming.”

Bellina Jones, 21, a shift lead at The Penny Ice Creamery nearby, got wind warnings on her phone. She was in the back of the shop washing a blender and came to the front as a customer said, “Tornado, get down!” Jones said she would have liked to receive a tornado warning on her phone, but noted the incident was very unusual.

“I get why nobody would think to do that here,” she added.

Power was back on Sunday, and by late Monday all 15 traffic lights that had been blown down were expected to be back up, said Scotts Valley Vice Mayor Derek Timm. The main damage was to Scotts Valley Middle School where a fallen tree wrecked several classrooms, he said.

“There’s still branches down, trees snapped off and ripped apart,” he said. “But our businesses have reopened. Some lost thousands of dollars. It’s the holiday season. It would be wonderful if the greater community could help them out.”

The Scotts Valley tornado was relatively small. It was just 30 yards wide and lasted 5 minutes, from 1:39 p.m. to 1:44 p.m, according to the National Weather Service preliminary report. On a  scale of 0 to 5, it was a 1.

But Garcia of the National Weather Service said he and other agency officials will evaluate to see if there’s anything they should do differently in the future. The agency might want to consider increasing phone alerts for severe thunderstorms in California, said Null, of Golden Gate Weather Services.

“You have to pull the trigger sometimes not knowing if it is going to verify,” Null said, citing the tsunami warning two weeks ago after a major earthquake 40 miles off the Humboldt County coast. “You can quibble about the details after the fact. But it’s a much better mode of operation to be safe than sorry.”

Bay Area News Group reporter Nollyanne Delacruz contributed to this story.

Originally Published: December 16, 2024 at 3:27 PM PST

San Francisco 49ers president of football operations/general manager John Lynch issued a statement on linebacker De’Vondre Campbell:

“We have suspended De’Vondre Campbell Sr. for three games due to conduct detrimental to the team. We will have no further comment on the matter.”

The intense weather seen all around the Bay Area this weekend made for long days for the employees at the National Weather Service’s Bay Area offices in Monterey. The first-ever tornado warning was issued for San Francisco on Saturday and a tornado was confirmed later that day in Scotts Valley in Santa Cruz County.

While having one tornado warning and another actual tornado all in one day might be common in other parts of the country, in the Bay Area, it’s a rarity.

As SFGate first reported, two National Weather Service Bay Area meteorologists had a long day Saturday as they started the day surveying damage in San Francisco and finished the day responding to the tornado in Santa Cruz County.

The two meteorologists, Brian Garcia and Dalton Behringer, started their morning on Saturday at the NWS Monterey offices.

At 5:50 in the morning, Behringer recalled clocking in as his colleagues who had been up all night working had just issued the first-ever tornado warning for San Francisco. Behringer said that a warning was issued due to what NWS had seen on the radar, which indicated there might have been a tornado in San Francisco.

Once the storm had passed, Behringer and Garcia drove up to San Francisco around 10:00 a.m. to investigate whether a tornado had touched down. They found the most intense tree damage on the western end of Golden Gate Park around the Bison Paddock.

“You couldn’t look a single direction without seeing a tree down somewhere or branches down somewhere,” Behringer recalled.

However, the meteorologists noticed something about the way the trees had fallen: they all fell in the same direction. They observed other notable damage in the Richmond District, the Presidio, the Mission, and Bernal Heights, but ultimately, they found no evidence of a tornado.

Behringer said that based on weather conditions, there might have been a funnel cloud or water spout while the storm was over the water near San Francisco. Still, because the peak of the storm happened before sunrise, there isn’t any documentation of that.

While the meteorologists were wrapping up in San Francisco Saturday afternoon, they got a call from their office alerting them that Scotts Valley had a tornado.

So Behringer and Garcia were then dispatched from San Francisco to Santa Cruz County, trying to get there in time to make the most of the remaining daylight hours.

When they arrived in Scotts Valley, the meteorologists saw many downed trees, downed power lines, damaged cars, and debris strewn across a retail center parking lot.

Unlike the scene in San Francisco, they saw what Behringer called the tell-tale sign of a tornado in Scotts Valley: debris strewn in multiple different directions.

“You look to your right and there’s a sign that fell this way and you look to your left and there’s a sign that fell the other way and that’s exactly the thing that we look for,” Behringer explained.

The team determined that the tornado was an EF1 strength because of the cars it flipped over.

In a month where Bay Area residents are getting lots of practice with emergency warnings, many are wondering: why was a tornado warning issued for San Francisco and not Santa Cruz County?

Behringer explained that several factors played into this. He noted that the NWS put a special marine warning in place when the storm was over the water near Santa Cruz. He said that the warning also advised about the possibility of water spouts as the storm passed over the water.

Behringer said the NWS issued a severe thunderstorm warning about ten minutes before the tornado hit. He added that the advised actions for a severe thunderstorm warning in the Bay Area are the same as those for a tornado.

Move to the lowest floor of your home or business and get to the most interior room,” he said.

“With a lack of ground verification, and just taking into account what had happened earlier in the day, and having the knowledge with us surveying that the tornado actually didn’t touch down in San Francisco, I think that kind of prompted a little hesitancy as far as going full tornado warning,” Behringer said of the warnings for the Santa Cruz County weather event.

Behringer noted these storms happen fast, and it is hard to get real-time information, especially in less-populated areas like Santa Cruz County.

In San Francisco, on Sundays, many residents made their own on-the-ground observations as they walked through the toppled trees throughout the city.

San Francisco residents Sharaya Souza and Matthew Crane walked through Golden Gate Park on Sunday, in part, to check on the bison in the park’s Bison Paddock after the storm.

“A couple of fences were crushed,” Crane said of the Bison Paddock, noting that while the bison were still enclosed, there was damage to the area around them.

Souza said she’s seeing more damage from this storm in the park than previous ones.

“Especially from last year, there were a lot of  fallen trees and we had really heavy rainfall, and I feel like this year it’s just taken an even bigger hit,” she noted

While the Bay Area is not known for tornadoes, Behringer said the conditions and the chances aligned Saturday.

“The fact that we were doing two separate damage surveys yesterday in the same day was quite astonishing,” he added, calling Saturday a “standout day” in his work four years with NWS Bay Area.

Behringer said his colleagues continue to survey the Scotts Valley location for more details. Saturday was certainly a noteworthy day for Bay Area weather, and one meteorologist will continue to study.