CA weather: What recent rain, heat means for drought, wildfires

The pendulum of Northern California weather is getting ready to swing again, from rain, hail, thunderstorms and snow showers at the start of this week to sunny and much warmer than average temperatures by the weekend.

Temperatures near Sacramento are expected to peak from 65 degrees Tuesday to 92 degrees Saturday, staying in the upper 80s to low 90s early next week, according to the National Weather Service.

Daytime highs near South Lake Tahoe will jump from the mid-30s Tuesday to the mid-70s this coming weekend. Both are roughly 10 degrees hotter than normal for this time of year.

The latest turnaround brings the same pair of questions Californians have grown used to asking:

Drought and summer water supply

In a California hydrology report on Friday, the state water officials wrote that April was ending with “average conditions,” but that this is not the case.

Sacramento and the central Sierra Nevada mountains each broke all time records for the least precipitation ever recorded between the beginning of January and the end of March.

Just a couple of weeks after winter storms dumped on the central Sierra Nevada in late April, statewide snowpack has melted down to 22% of average as of Tuesday, falling from 35% on April 26, according to the state Department of Water Resources. The southern Sierra range is now at just 9% of average.

“As we get that snowpack building through winter and it gets to spring, the snowmelt becomes the foundation of your summer supply,” Michael Anderson, the state climatologist, said in a media briefing with reporters Tuesday on drought conditions. “As that melts out, then you move into storage until those fall rates return and the cycle starts over.”

But as normal temperatures and precipitation patterns bounce between extremes, Anderson said, this normal cycle is disrupted.

“We used to not have to worry about warm anomalies in the wintertime drying out the landscape. That was a summertime thing, ”Anderson said. “Now it really is, we get these long breaks (in precipitation) like we saw this year.”

Anderson noted the stark comparison of March in the first year of current drought, 2020, and March 2022. Statewide precipitation in March 2020 reached 95% of average; this year, it was just 30%. March 2020 was 1.3 degrees cooler than average; March 2022 was 3.6 degrees warmer than average.

He said the state’s snowpack peaked about a month earlier than normal, in early March rather than early April.

Climate change is a large part of those anomalies, state water officials on Tuesday’s briefing said.

The anomalies are impacting reservoir levels as well. Eleven of the state’s 17 reservoirs are below 80% of average, according to Department of Water Resources data updated Tuesday. The two largest, Lake Shasta and Lake Oroville, were at 48% and 70% of average, respectively.

Wildfire risk

Fire agencies and climate experts have advised that this is a wildfire season for California.

That hasn’t materialized yet, with mild temperatures and scattered showers in recent weeks.

In early April, the weather service issued its earliest ever spring warning flag for northern California due to dry, hot and windy conditions.

But the Sacramento Valley hasn’t been under a flag for more than a month since then, thanks to a large number of floods.

That streak won’t continue forever. As the summer months arrive, it will bring drier and more receptive wildfire fuels in many parts of the state.

In the immediate short-term, the National Weather Service Storm Prediction Center’s fire weather outlook as of Tuesday showed no heightened fire risk within California.

Those forecasts do, though, show “critical” fire conditions elsewhere in the West, across New Mexico, Arizona and Colorado over at least the next few days, along with “elevated” Nevada and Utah.

California’s most dangerous wildfire conditions in recent years have often not come in the hottest point of the year, but rather in early autumn, when lingering heat tends to coincide with gusty winds and dry vegetation.

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Michael McGough anchors The Sacramento Bee’s breaking news reporting team, covering public safety and other local stories. A Sacramento native and lifelong capital resident, he interned at The Bee while attending Sacramento State, where he earned a degree in journalism.

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