How meteorologists tracked the tornado risk in Scotts Valley, San Francisco

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.