California’s wet winter lowered the risk of big fires, experts say

This winter, researchers predicted record-breaking snowpack and precipitation would mean a reduced risk for massive wildfires. 

That theory has held up: According to the National Interagency Fire Center’s August outlook, the potential for fire in California is normal, with some areas marked as below normal. 

Craig Clements, director of the Wildfire Interdisciplinary Research Center at San Jose State, said that’s a big deal for California. In recent years, he’s often seen the state’s outlook in the red — meaning above normal risk for significant fires. 

“Right now, we are one of the lowest acres burned for this time of year in the last 10 years or more because of the wet winter,” said Clements. “Most of the fires started, there’s been very small acreage burned, except for the York Fire.” 

Last winter’s precipitation brought necessary moisture to a drought-stricken California. That moisture, after being soaked up by the soil and flammable biomass, like fallen forest trees, reduces the risk for massive wildfires.

California’s snowpack is double the average for May, survey finds

Some researchers had speculated this moisture might cause a boom in vegetation growth, thereby creating more fuel for fire in the hot months. But Clements said measurements he’s done of new shrub growth at some of his field sites show that it’s not a big concern at the moment. 

“The amount of mass that has increased because of the rainfall is not as big of a consideration as… the fuel moisture content,” he said. “The wetter the fuels, the lower risk of ignition, so it’s been a positive thing for fire risk so far.” 

Helen Dahlke, a surface and groundwater expert with UC Davis, said most of the winter snowpack has melted. But she can say with certainty that it accomplished what many researchers hoped it would, in terms of fire and drought outlook. 

“Only small portions in northern California, along the north coast, and in the Mojave Desert, still show indicators of drought,” Dahlke said. “But the rest of the state, at least from a surface water perspective, looks like we have really replenished all of our surface water stores.”

She said the rate of snowmelt wasn’t unusual, even with recent weeks of intense heat. However, California did see snowpack levels peak earlier than usual, which Dahlke said is a symptom of climate change. 

While researchers can agree last winter’s precipitation was positive for California, it doesn’t mean the potential for big fires is completely gone. Clements said those big fires tend to appear in August. While the outlook for fire potential is currently lower for this month than it has been in recent years, he said day-to-day weather could impact the forecast.  

“If we do get a big heatwave, a severe heatwave, that could change the fuels,” he said. 

But historically, Clements said wet winters are often followed by milder fire years. He compared this year to 2019; that year, sandwiched between two particularly intense fire years, was fairly uneventful in comparison.