Winter Is Coming Back to California With a Series of Wild Storms

A man uses a paddle board to make his way through flooded streets in Sebastopol, California in February.
Photo: AP

By mid-May, California is usually leaning pretty hard into the summer dry season. But a bizarre series of storms will have weather maps looking more like winter than spring.

Inches of rain, feet of snow, and gusty winds will buffet Northern California over the next week and a half. Records could be broken and it could even be good news for fire season, at least in the short term.

The first in a series of storms should arrive Wednesday morning. The National Weather Service is forecasting up to 3 inches of rain through Thursday from Big Sur to Marin County north of San Francisco and other parts of Northern California, though areas could see locally higher amounts. Umbrellas will be pretty useless as winds gust to 40 mph.

The cool air accompanying the storm also means mountain snow will fall. Winter storm warnings cover the Sierra Nevada, and the National Weather Service is calling for 24 inches of snow, though some high peaks could pick up 35 inches. All this is just from round one, as the parade of storms is set to continue into next week, repeatedly blitzing the northern half of the state. Later next week, Southern California could get in on the action, too.

That means the state will continue to build on its already prolific snowpack from this winter. California Department of Water Resources data show that all parts of the Sierra Nevada currently have snowpack anywhere from 120-133 percent above normal for this time of year, after a winter that saw some locations receive more than 50 feet of snow. That’s helped the state climb out of drought save a small pocket of what the U.S. Drought Monitor calls “abnormally dry” conditions on the U.S.-Mexico border. The new snow and rain will keep things damp and tamp down early season wildfire risk, though the extra vegetation they help grow could eventually end up as flammable fuel later this year.

The source of the storms isn’t quite an atmospheric river, a meteorological phenomenon where fast-flowing air taps moisture from the tropical Pacific and ushers it to California. These rivers in the air are responsible for the majority of California’s winter precipitation. Rather, it’s a strong jet stream blowing across the Pacific that will help usher rain and snow toward the Golden State. The pattern is really weird for this time of year, when high pressure normally builds over California and keeps storms at bay.

There are a couple reasons for the breakdown of that normal pattern. Daniel Swain, an atmospheric scientist at the University of California, Los Angeles who has extensively researched California, pointed to a shift in the Madden Julien Oscillation (MJO) as one potential cause. The MJO is characterized by a swath of clouds and thunderstorms that moves back and forth around the western Pacific and affects weather downstream. Swain wrote that it’s “been very active for the time of year” and has helped strengthen the jet steam enough to steer storms to California.

But climate change could also be playing a role. Swain pointed to the unusual heat that’s been gripping the Arctic as well as disappearing sea ice—both symptoms of climate change—as another potential driver of the weird jet stream pattern. A growing body of research has linked changes in the Arctic to unusual weather patterns to the south, and this could be no exception. At the same time, Swain’s own research also shows that weather whiplash between wet and dry years will become more common for California.


more recommended stories

  • California Plans Blackouts to Fight Wildfires, and Solar Power Is Looking Better Than Ever

    Photo: Mario Tama (Getty) It’s wildfire.

  • Kids Strike Around the World to Raise the Alarm on Climate Change

    Look at this cute British baby..

  • The 2019 Hurricane Season Shouldn’t Be That Bad (Hopefully, Maybe)

    Residents in Florida are still rebuilding.

  • Tornado Kills 3 on Eighth Anniversary of America’s Deadliest Twister

    No thank you.Photo: AP Eight years.

  • Segregation Has Left a Legacy of Asthma and Pollution in California Cities

    Lots of elements factor into whether.

  • Trash-Burning Power Plants Wind Up in Our Most Marginalized Communities, Report Finds

    The Harrisburg incinerator in PennsylvaniaPhoto: AP.

  • Atlantic Hurricane Season Could Be Getting a Head Start This Week

    Atlantic hurricane season officially starts on.

  • The Southern Plains Is at High Risk of ‘Violent’ Tornadoes on Monday

    Damage from April tornadoes in the.

  • State Rejects NYC’s Big New Pipeline Project—For Now

    NYC, baby.Photo: Getty On Wednesday night,.

  • A Real Bird Watcher Watches Netflix’s Animated Tuca & Bertie

    A mixed flock.Image: Netflix/Pavrabec/Diego Delso/Mdf/Fernando de.

  • A Huge Swath of the U.S. Could See Tornadoes Over the Next Five Days

    Photo: Getty A dangerous weather setup.

  • Scientist Composes Game of Thrones-Worthy Song From Climate Change Data

    Screenshot: YouTube Have you ever wondered.

  • A Quarter of West Antarctica’s Ice Is Now Unstable, Study Finds

    Stop me if you’ve heard this.

  • It Was 84 Degrees in Northern Russia This Weekend

    Photo: AP Scattered clouds gave the.

  • Giant Pile of Toxic Coal Ash Is Being Moved From Puerto Rico to Florida, Sparking Outcry

    Not the Puerto Rican coal ash.

  • Wildfires Smoke Is Enveloping Mexico City and Could Reach the U.S. This Week

    Photo: AP It doesn’t matter if.

  • Thanks to Fox News, Republicans Now Hate the Green New Deal

    Photo: AP For a brief, shining.

  • Google Wants to Use AI to Track Pollution from Every Power Plant on Earth

    Not a satellite, but that is.

  • The Most Toxic Place You Could Go This Weekend Might Be a Nail Salon

    Photo: Getty I’m somewhat obsessed with.

  • New Exhibit Asks Us to Radically Rethink How We Live With Nature

    It was a bad week if.

  • Teaching Girls About Climate Change Can Help Their Parents Care Too, Study Finds

    Photo: Getty Kids are out here.

  • Why Flight Attendants Should Lead the Fight Against Climate Change

    Photo: Getty In recent months, the.

  • Most National Parks Have ‘Significant Air Pollution Problems,’ New Report Finds

    The Rocky Mountain National Park in.

  • Scientists Say They’ve Cooked Up an Endlessly Recyclable Plastic

    Behold, the regular evil plastic we.

  • Scientist Dream of a Future Where Your AC Unit Sucks Carbon Out of the Sky

    Air conditioners rule the world.Photo: Getty.

  • How Students Convinced Beto O’Rourke to Stop Taking Fossil Fuel Money

    Photo: Getty The transformation of Beto.

  • New Board Game Challenges Players to Design a Perfect Planet

    This is how you prepare to.

  • Presidential Candidate Jay Inslee Proposes Shutting Down America’s Coal Industry in a Decade

    Photo: Getty Jay Inslee, the first.

  • The Last of the Arctic’s Old Sea Ice Is on the Verge of Vanishing

    Photo: Getty Pour one out for.

  • The House Just Passed Its First Climate Change Bill in a Decade, and That’s Not Even the Sad Part

    Here is the moment Democrats introduced.

  • Powerful Cyclone Bears Down on India, Forcing Millions to Evacuate

    Cyclone Fani is bearing down on.

  • In World First, UK Declares Climate Change Emergency

    Photo: Getty The House of Commons.