California's Snowpack Shrinks, Igniting Concerns of Early Wildfires

California’s snowpack is dwindling, and climate scientists believe another record-breaking hot summer could be in the cards, ramping up the possibility of an early fire season.

The state’s snowpack is at 14% of average peak snowpack, down from 96% on April 1 — the date snow scientists consider the height of the snowpack, according to the state. The snowpack is melting a little faster than usual, but state scientists said the rate of snowmelt isn’t entirely abnormal. However, climate scientists believe early snowmelt this year could be partly due to human-caused climate change.

Andy Reising, manager of the California Department of Water Resources’ snow surveys and water supply forecasting unit, said it’s important to understand that snow is not melting uniformly across all watersheds.

With three years of around average snowfall, Reising isn’t worried about water supplies with state reservoirs at 116% of normal for this time of year. River forecasts in the north end of the Sierra Nevada are about 100% of normal, although that story changes further south along the range and into the mountains of Southern California.

But what he’s concerned about is that the faster rates of snowmelt — especially in the south — could exacerbate wildfire danger in this region.

“The south had a really lousy year, and the mountains are super dry,” Reising said. “That’s why we had the fires back in January. The southern part of the state, where we don’t have snow, is a really, really high-risk area.”

Roger Bales, a hydrology and water resources engineering professor at UC Merced and UC Berkeley, said snow melting between April and June is normal. Still, when looking at the snow cover from an aerial view, he said it’s clear that the snowpack is getting thinner. He sees faster rates melt across all parts of the Sierra Nevada, but they are more pronounced in the south.

When looking at state historical data, Bales said the snowpack across the Sierra Nevada this year is visually and strikingly low compared to the 30-year average.

“You can see the difference in the data,” Bales said. “As you warm the climate by each degree Fahrenheit, the snowline goes up about 250 feet in average long-term warming. But that doesn’t mean we won’t have snow at high elevations.”

In the long run, despite year-to-year variability, Bales said he sees California struggling to maintain a healthy snowpack as the snowline moves higher and the snowpack eventually gets smaller.

That means droughts and wildfire risk could increase over time as the world continues to burn fossil fuels, causing human-caused climate change.

“Faster melt rates are caused by a warmer climate,” Bales said. “It’s not good for wildfire risk, and soils are going to dry out faster about a month after the snow melts.”

However, over the next few months, the more harmful issue isn’t just about faster snowmelt. UC Merced climatology professor John Abatzoglou worries that a hotter-than-normal summer will follow the speedier snowmelt rate. Last summer was the world’s hottest on record. The same goes for California.

“The combination of a little earlier-than-normal melt out of our snowpack, along with what is likely going to be another warm summer, is sort of shifting the odds for elevated fire potential across the state,” Abatzoglou said. “Over the past 50 years, summer has taken the medal in terms of the fastest warming season.”