Atmospheric rivers are becoming a "double-edged sword" for California, an expert has told Newsweek.
The weather phenomenon involves concentrated corridors of tropical moisture that travel through the atmosphere. When they make landfall, they unleash heavy rain and snow in higher areas.
California has experienced many in recent weeks, with a series of atmospheric rivers bringing floods and landslides across the state, and another causing a severe blizzard across the Sierra Nevada. Storms caused by the phenomenon also swept across the state at the beginning of 2023 and into spring.
While precipitation is a good thing for the usually dry state, it also has negative consequences, Breanna Zavadoff, an assistant scientist at the University of Miami's Cooperative Institute for Marine and Atmospheric Studies, told Newsweek.
Zavadoff, whose work specializes in predicting atmospheric rivers using regionalized weather models, said: "It's pretty concerning. One reason is because predictions have shown that atmospheric rivers are going to bear the larger burden of being California's water resources in the future. So California would be getting a larger fraction of its annual precipitation from atmospheric rivers in the future.
"They're going to need them to get water, but they're going be so strong that every time you're hit by one, or nearly every time, you're going have a consequential impact. You're getting the water you need, but you're getting too much at once. You're busting a drought, but you're getting landslides. It's a very double-edged-type sword, especially for water management resources."
As climate change worsens, California and the wider West seem to be getting more extreme weather patterns. The state was in a severe drought in recent years—however, the 2023 atmospheric rivers caused so much rain and snow that it ended. It also caused higher than average snowpack levels in the mountains, which fed down into the state's rivers and reservoirs.
Zavadoff said atmospheric rivers "are a huge contributor to snowpack, which is really important for California and the West."
But last year's storms also caused flooding, landslides and severe disruption.
Zavadoff warned that they are coming in quicker succession, meaning that the state does not get a break.
She added: "Last year was, as you know, a wild year, but the drought ended. ... now we're receiving a ton [of atmospheric rivers] again. So they're going to become more intense and more frequent in the future and they're going to become a larger fraction of annual precipitation for the West."
Do you have a tip on a science story that Newsweek should be covering? Do you have a question about atmospheric rivers? Let us know via science@newsweek.com.
Uncommon Knowledge
Newsweek is committed to challenging conventional wisdom and finding connections in the search for common ground.
Newsweek is committed to challenging conventional wisdom and finding connections in the search for common ground.
About the writer
Robyn White is a Newsweek Nature Reporter based in London, UK. Her focus is reporting on wildlife, science and the ... Read more
