Warning Signs Of Widespread Drought Loom Over California

Warning Signs Of Widespread Drought Loom Over California
Researchers measuring snow in California last week. (Photo: AP)

Less than a year after being declared drought-free, California is in trouble again.

The U.S. state has had a winter to forget, all but capped off by a February with little to no precipitation across a wide swath of California. While there’s still time to make up some ground with a wet March, the odds are that the state won’t be able to make up the huge precipitation deficit as it heads into the dry season. The wild swings in the Golden State’s weather fortunes are exactly the type of patterns researchers have found are becoming more likely as the planet heats up.

Winter is when California picks up most of its precipitation for the year, which in turn fills reservoirs and stacks up as snow in mountains that melts throughout the dry summer and fall. The state plunged into a deep drought that really cranked up in 2014 and lasted until a series of wet winters dented it starting in 2017. While it’s way too early to say this year’s dry winter is the start of a similar major drought, there are some serious concerns on the horizon.

California snowpack stands at less than 50 per cent of normal across the Sierra Nevadas, according to the latest data from the California Department of Water Resources. February is when the deficit really started to take hold, though. Outside of a few parts of Southern California, rain and snow were in very short supply throughout the state. Parts of Northern California received no precipitation at all despite February normally being one of the wettest months for the state, marking the first time on record that’s happened. I mean seriously, this is one bleak map:

Yikes. (Image: WRCC)

As a result, a quarter of the state’s area—home to nearly 6 million people—is now in drought, and it could worsen without precipitation. While there are a few showers on the horizon, they’re not too likely to bring any major relief, particularly as most will miss Northern California where drought conditions are most likely to worsen.

“It’s virtually impossible at this point for March/April precipitation to completely make up the very large accumulated seasonal deficit, but a series of last-minute storms would still help delay the peak of fire season,” Daniel Swain, a UCLA climate researcher, told Gizmodo in an email. “Hopefully that will happen, but it does appear that California will probably be experiencing some degree of drought conditions heading into the long, dry summer.”

The source of California’s abnormally dry February will be a familiar one if you followed the 2014-17 drought. A ridge of high pressure has camped over the North Pacific just offshore from the state, shunting storms to the north. Meanwhile, warmer than normal conditions have cut snowpack down from where it could be. While the location of the ridge is slightly different than the previous death ridge, and the heat isn’t quite as potent as what drove last decade’s drought, the impact so far is similar.

It’s a jarring turn of fates back to drought after the state just had some of its on record. But it’s also what is likely to keep happening as the planet heats up.

“Both of these conditions—the increasingly wide swings between very wet and very dry conditions and the anomalous overall warmth—are consistent with what we expect to see in a warming climate in California,” Swain, who has extensively studied this exact topic, said.

The points to the need for water managers, firefighters, and anyone with a pulse in California really to stay on top of the risks posed by both extreme precipitation and extreme lack of it. As if on cue, the Mann Fire ignited in the suburbs of Los Angeles on Tuesday afternoon, prompting mandatory evacuations in what could be a harbinger of the late spring and summer to come.