California Extreme Weather Is the New Normal

California's bout of extreme wet weather could become the new normal as climate change worsens, a researcher has warned.

A bomb cyclone battered the state on Tuesday, bringing down trees and power lines. At least one person was killed after a tree fell onto a vehicle, the Los Angeles Times reported. Early on Wednesday, more than 130,000 customers were still without power, according to PowerOutage.us.

Tom Corringham, a research economist at Scripps Institution of Oceanography at UC San Diego, told Newsweek that California could expect more of these extreme weather patterns in the future as the climate warms.

"When people ask if California is getting wetter or drier, the answer is both. Rising temperatures in California dry out our landscapes, leading to longer droughts and more severe fire seasons," said Corringham, whose research focuses on the social and economic impacts of climate change.

"Higher temperatures also allow the atmosphere to hold more water vapor, leading to more intense storms. This has been described as 'hydroclimate whiplash' or 'weather on steroids.'"

California's recent spate of wet weather started in late December and continued to mid-January. At the end of February the state was hit by strong snowstorms, even in areas used to bone-dry conditions such as Los Angeles.

Unlike the bomb cyclone seen in December, this week's storm has been concentrated mainly on the coast. Although wet weather had been forecast, the storm hit much harder than expected. It is particularly bad in the south of San Francisco Bay and Monterey Bay. The National Weather Service warned of high winds as well as rain from San Francisco to San Diego on March 21.

Heavy snow is also expected in some mountainous areas of Southern California. In high elevations, up to 4 feet of snow could accumulate.

California has been in the grip of a drought for two decades, so the wet weather was initially welcomed by some. In February, drought conditions did improve across much of the state.

Back in October 2022, large portions of California were in an extreme or exceptional drought. The rest of the state was in a severe drought, with very small portions in a moderate drought or abnormally dry.

A map from February 28 looked very different. Most of the state was classified as abnormally dry, with some areas not in a drought at all. Some small portions were in a moderate-to-severe drought.

It remains to be seen whether this week's storm will alter the state's drought status further.

Even if it does, experts have warned that it is only a short-term solution.

Extreme dry periods followed by extreme wet periods can lead to more problems. When land has been dry for a long time, the ground can become parched, meaning that water does not saturate. This can cause flooding.

"In California's future we expect to see shorter winters and more precipitation falling as rain instead of snow. This will generate floods but also make it harder to capture water in our reservoirs, making drought impacts even worse," Corringham said.

"Most of the flooding that occurs in California is due to atmospheric rivers and these are projected to get longer, wetter and wider in the coming decades."

The bout of cold weather over the winter meant that snowpack in the Sierra Nevada was at record levels. Come spring, the snowpack melts and gradually replenishes California's reservoirs. However these atmospheric rivers—a corridor of concentrated, tropical moisture traveling through the atmosphere—can cause it to melt all at once, causing even more flooding.

Experts believe these extreme weather events are all a direct result of climate change. As wet winter storms become the new normal, Corringham said there were ways to prepare for the extreme conditions.

"Fortunately, there are steps we can take to limit the negative impacts on our communities and our livelihoods. We can strengthen our dams and levees and restore our natural floodplains," Corringham said.

"We can use improved storm forecasts to give reservoir operators greater flexibility. We can strategically flood farmland to store water underground in what is called 'managed aquifer recharge.' Finally, we can invest in our water delivery systems to get more water where it needs to go during droughts."

Corringham added: "But unless we make a rapid transition away from fossil fuels to renewable energy, the weather in California will get more extreme and unpredictable. We're taking promising steps in the right direction, but we still have a long way to go."

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