Fires sweep through Santa Cruz in January. Is this our new normal?
Climate change will create conditions for winter fires more often, but don’t rule out tiptoeing around other disasters in Santa Cruz County and statewide.
The big disaster concerns for Santa Cruz County this winter were thought to be debris flows — damage from the summer CZU fires causing potentially massive, deadly landslides once the winter rains hit.
But those winter rains haven’t come, and the wildfire season effectively hasn’t stopped.
The beautiful beach weather that graced Santa Cruz and the Bay Area last weekend turned destructive Monday night, as strong offshore winds blasted the mountains and coast, downing trees and power lines. By Tuesday morning this combination had set off more than a dozen wildfires in Santa Cruz County. As of Tuesday evening, more than 100 homes had been evacuated.
It’s the latest example of how climate change is impacting our community and state. Researchers are forecasting that California is now in an era of increased weather variability: it’s possible most future winters might actually be wetter than historical averages. But other years will be much drier, and the winter rains could start later, extending the fire season.
This could create a cycle of drought, fire, flood, and debris flows year after year — all four could even happen in the same year.
Lead-up to disaster
This weekend set temperature records all across the Bay Area. San Francisco hit 77 degrees, shattering a record of 76 previously set in 1920. Santa Cruz didn’t break any records, but temperatures were “well above average,” according to Gerry Diaz, a meteorologist with the National Weather Service.
Then, a strong pressure gradient built up that brought in hot, dry, air from inland to the coast — an unusual event in the winter.
“In terms of just the winds themselves it’s fair to say it’s going to be a historical event,” Diaz said. These kinds of winds during the month of January are, he said, “unprecedented.” Gusts reached 35 to 45 mph in the mountains and between 25 and 35 mph by the coast. Daniel Swain, a climate scientist at UCLA who studies regional climate extremes, said our region on rare occasions has experienced strong winter winds over the years; the difference is their combination with hot, dry conditions.
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Precipitation in the Santa Cruz Mountains is at about 27% of normal right now. It wasn’t just the holiday weekend weather that created dry fire fuel, it was months of below-average winter rain.
“We occasionally get these strong offshore winds, and usually if they happen in the middle of winter, you might get some wind damage, and trees down, and fences knocked over,” Swain said. If they do happen in the winter, it doesn’t typically create fire risk like it does in the summer and fall. Usually in January the Santa Cruz mountains are “wet enough in most places that if you lit a match, you couldn’t start a fire if you tried,” Swain said.
Swain said that while the intensity of the wind event was abnormal, he hasn’t seen evidence to link the winds in and of themselves to climate change.
What is true, however, is that increasing temperatures and lower precipitation have created a tinderbox; so when strong winds, or a dry lightning storm, or a gender reveal party come along, conditions are often primed for fire in a way they wouldn’t normally be — even in the winter.
Grasses and bigger vegetation, like trees, have different time-scales to get to dangerous levels of dryness. The short burst of heat over the weekend dried out the grasses, but it took months of record heat and little rain to dry out the trees.
‘Something we can expect . . .’
These are conditions that will happen again, even in the winter. “It’s becoming increasingly clear that the delay of the rainy season — certainly in the autumn months — is something we can expect with climate change,” Swain said.
Diaz said the last time a red flag warning was issued in January in Santa Cruz County was in 2014, and eventually fires did break out during that winter season. But other examples of winter fires in the region are few and far between.
Swain said that according to his research, they will probably remain a rare occurrence. “It may only happen 10, 20% of the years, but that’s a big increase from approximately 0% of the years, historically,” he said.
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Meanwhile, the current plague-ridden, never-ending fire season rages on in Santa Cruz. But Diaz says hope is in sight.
“It’s looking like we have an increased chance for some potential for precipitation, Friday and going into the weekend,” he said.
In an ideal world, it will be just enough to put out the remaining fires, but not enough to trigger debris flows and mudslides. We’ll have to get used to this tiptoeing around disasters.