Tag Archive for: Climate

La Niña Arrives, Threatening to Stoke Droughts and Roil Markets

/in , , /by /Bloombergby Brian K Sullivan

A weather-roiling La Niña appears to have emerged across the equatorial Pacific, setting the stage for worsening droughts in California and South America, frigid winters in parts of the U.S. and Japan and greater risks for the world’s already strained energy and food supplies.

The phenomenon—which begins when the atmosphere reacts to a cooler patch of water over the Pacific Ocean—will likely last through at least February, the U.S. Climate Prediction Center said Thursday. There is a 57% chance it be a moderate event, like the one that started last year, the center said.

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Late October Rains Could Dampen Wildfires and Help With Drought, Forecasters Say

/in , , /by /Los Angeles Timesby Paul Duginski

A wetter than average forecast for late October could dampen wildfires burning in Northern California and help ease drought conditions, according to the National Weather Service.

The latest weather outlook for the latter part of this month calls for above-normal precipitation in California, with possible high-elevation heavy snow in the Sierra Nevada and the Cascades. There is also potential for an atmospheric river between Oct. 21 to Oct. 27, forecasters said.

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Atmospheric Rivers Left California Mostly Dry in Water Year 2021

/in , , /by /Water News Network Quoted: San Diego County Water Authority

The Center for Western Weather and Water Extremes, or CW3E, at Scripps Institution of Oceanography, released its report October 11 on atmospheric rivers during Water Year 2021.

The report, “Distribution of Landfalling Atmospheric Rivers over the U.S. West Coast During Water Year 2021: End of Water Year Summary” shows that more atmospheric rivers landed on the U.S. West Coast in Water Year 2021 than in Water Year 2020. But the majority of those storms reached the Pacific Northwest, not California, where drought conditions have impacted water supply.

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La Niña Brings More Worries Amid Drought

/in , , /by /The Daily Journalby Corey Browning

Though it’s unclear what the effects of the La Niña climate expected this winter will be for Northern California, drought-ending rain is likely not among them.

The climate pattern brought on by cooler-than-usual surface water in parts of the Pacific Ocean creates varying weather globally, but historically the phenomena has meant drier conditions in the southern part of the state and wetter conditions in the Pacific Northwest.

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Atmospheric Rivers-Water Year 2021-drought-climate

Atmospheric Rivers Left California Mostly Dry in Water Year 2021

/in , /by

The Center for Western Weather and Water Extremes, or CW3E, at Scripps Institution of Oceanography, released its report October 11 on atmospheric rivers during Water Year 2021.

The report, “Distribution of Landfalling Atmospheric Rivers over the U.S. West Coast During Water Year 2021: End of Water Year Summary” shows that more atmospheric rivers landed on the U.S. West Coast in Water Year 2021 than in Water Year 2020. But the majority of those storms reached the Pacific Northwest, not California, where drought conditions have impacted water supply.

“The report on atmospheric rivers shows the variability in weather across the state from year to year,” said Jeff Stephenson, Water Resources Manager with the San Diego County Water Authority. “Through our partnership with CW3E and the AR forecasting tools they’ve developed, it better prepares us in management of our water resources using regional storage. This storage, in conjunction with developing multiple water supply sources in the San Diego region, has prepared us for years when rainfall levels are below normal in the region.”

The summary report from CW3E

Water Year 2021 experienced a total of 69 landfalling ARs over the U.S. West Coast, 4 more than Water Year 2020.
• While WY 2021 experienced more ARs, a much larger majority of the ARs only impacted the Pacific Northwest.
• California only experienced AR conditions (IVT >250 kg m–1 s–1) from 36 separate ARs during WY 2021, compared to 43
during WY 2020.

Atmospheric Rivers-Water Year 2021-drought-climate

Distribution of Landfalling Atmospheric Rivers over the U.S. West Coast During Water Year 2021: End of Water Year Summary. Graphic: Center for Western Weather and Water Extremes

Fewer Atmospheric Rivers in California

The lack of AR activity over California for two consecutive water years has resulted in a substantial lack of precipitation.
• A large portion of California received <30% of the normal precipitation for both Water Year 2020 and 2021.
• Coastal Washington and Oregon was the only location in the Western U.S. to receive near or above normal precipitation
during both water years, which is also the region that received a majority of the AR activity.

California experienced strong or greater magnitude AR conditions only three times during WY 2020 and 2021 combined

Atmospheric Rivers-CW3E-drought-climate

Atmospheric Rivers-CW3E-drought

The San Diego County Water Authority partnered with the Scripps Institution of Oceanography, Center for Western Weather and Water Extremes, at UC San Diego in 2020 to better predict atmospheric rivers and improve water management before, during, and after those seasonal storms. The Center and its partners share best practices in forecast-informed reservoir operations, increased research around atmospheric rivers and droughts, and develop strategies for mitigating flood risk and increasing water supply reliability.

For additional details and graphics go to: https://bit.ly/3mKhkcR

‘Extreme Year’: Past 12 Months Among the Driest Ever in California History

/in , , /by /The Union Democratby Guy McCarthy

The current ongoing two-year dry period in California, punctuated by the third-driest water year on record for the Central Sierra, is part of California’s overall arid fate so far in the 21st century, according to the state Department of Water Resources.

The Golden State’s hydrology now increasingly resembles conditions in the Colorado River Basin this century, where multiple, consecutive, drier-than-average years are mixed with an occasional wet year. California’s last wet water year was 2016-2017, the second-wettest on record.

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California and the West Can See Small Glimmers of Hope in Weather Outlooks for October

/in , , /by /Los Angeles Timesby Paul Duginski

Outlook maps for October temperature and precipitation in the U.S. offer a glimmer of hope for California and parts of the West. For the first time in months, California’s precipitation outlook map isn’t colored a desiccated brown, indicating drier-than-normal conditions.

Likewise, the temperature outlook map isn’t glowing red, resembling a stove-top burner set on high.

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What is La Niña ?

/in , /by /AccuWeatherby Mary Gilbert

The term La Niña may be one that casual weather observers as well as aficionados hear meteorologists using from time to time, especially when breaking down long-term weather trends or providing a sneak peek at conditions expected during an upcoming winter or hurricane season. But, what exactly is La Niña? Let’s take an in-depth look.

The key to how winter in the United States may unfold often lies thousands of miles away in the open waters of the equatorial Pacific Ocean. It’s there where the roots of a climatological phenomenon known as La Niña originate and eventually help shape weather patterns worldwide.

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California’s Rainy Season Is Changing. Here’s What That Means for Already Worsening Fire Danger.

/in , , /by /ABC10by Monica Woods

After two dry years, the California is in desperate need of rain and snow. October marks the beginning of California’s new water year, which will run through Sept. 30 next year.

This also signals the transition from the long, dry summer months to the wetter time of year. But new research is showing a delay to California’s rainy season.

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A 7.1 Earthquake Couldn’t Kill this Mojave Desert Town. But a Water War Just Might

/in , /by /Los Angeles Timesby Thomas Curwen

On the northern edge of the Mojave Desert, a new trauma has awakened old concerns: What happens if a town’s water gets shut off? The question keeps Danny Tolbert awake most nights. Two years ago his taps ran dry after a 7.1 earthquake nearly brought down his house and community. That was three months before his stroke, before he learned how diseased his heart was.

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