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FIRO-Scripps-Law-Water Management

New California Law Taps Science to Improve Water Management

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

Legislation signed into law by California Governor Gavin Newsom ensures the state has the science and weather forecasting tools it needs for more flexible reservoir operations. The bill, AB 30, makes breakthrough water management technology standard for the California Department of Water Resources.

The legislation was introduced by San Diego Assemblymember Chris Ward and co-sponsored by the Sonoma County Water Agency and the San Diego County Water Authority. The bill was supported by the Water Authority’s partner, UC San Diego’s Scripps Institution of Oceanography.

The strategy is called forecast-informed reservoir operations, or FIRO, and it complements Gov. Newsom’s California Water Supply strategy released in August 2022 calling for more reservoir storage capacity to capture runoff from big storms, often fueled by atmospheric rivers. The governor and Legislature have already provided funding for state water managers to integrate the strategy.

FIRO-Science-water management

Diagram illustrating the FIRO process to develop an adaptive water control manual. Graphic courtesy Scripps Institution of Oceanography Center for Western Weather and Water Extremes

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How Tracking Atmospheric Rivers Could Transform California’s Reservoir Levels During Drought

/in , , /by /San Francisco Chronicleby Jack Lee

Atmospheric rivers can wreak havoc on the West Coast. These “rivers in the sky” stream enormous amounts of moisture from the tropics to western North America — double the flow of the Amazon River, on average. This moisture can produce downpours that cause widespread flood damage. From 1978 to 2017, this damage amounted to $1.1 billion per year according to a 2022 study. But atmospheric rivers are also crucial for life in California.

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CW3E Kicks Off the Water Year 2023 West-WRF Forecast Season

/in , , /by /Center for Western Weather and Water Extremes

The Center for Western Weather and Water Extremes (CW3E) at Scripps Institution of Oceanography runs a weather prediction system called ‘West-WRF’ that has been optimized for predicting rainfall along the West Coast primarily from atmospheric rivers (AR). Forecast data from West-WRF is used by water managers to improve reservoir operations and to inform CW3E AR reconnaissance activities.

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Few Strong Landfalling Atmospheric Rivers Reach California

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

Few landfalling atmospheric rivers in the current water year have reached California, now in the third year of a statewide drought.

The latest update from the Center for Western Weather and Water Extremes, Scripps Institution of Oceanography at UC San Diego, shows that Water Year 2022 started strong in October, but weaker storms did not ease dry conditions.

California Snow Drought Ends in Dramatic Fashion, While Other States Still Deal with Shortage

/in , , /by /CNNby Allison Chinchar
Thanks to multiple atmospheric river events, average snowpack in California has gone from 18% to 98% in just two weeks.
“Increases in snowpack of this size are not common, but also not unprecedented,” Julie Kalansky, deputy director of operations for the Center for Western Weather and Water Extremes (CW3E), explained.
Kalansky pointed out previous studies have shown a jump on this scale can happen about twice every three years, but usually over the course of an entire winter, not just the month of December. While they don’t have the exact rankings for each month of the year, “most of the storm events in the study we referenced for the above calculation were in the second half of December and later into the season,” Kalansky added.
The sudden change gives California its wettest start to the Water Year in more than 40 years, thanks to several drought-denting rain and snow systems pushing through the area in recent weeks. The Water Year runs from October 1 through September 30 of the following year.
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Scripps, CW3E and Yuba Water Agency Launched Weather Balloons During Atmospheric River

/in , , /by /YubaNet and CW3Eby YubaNet

On Sunday morning, during the atmospheric river event in Northern California, scientists from the Center for Western Weather and Water Extremes (CW3E) at the Scripps Institute of Oceanography at UC San Diego and their partners at Yuba Water Agency launched weather balloons to gather data on the AR and its impacts on reservoirs.

Atmospheric River events in Water Year 2021

(Editor’s Note: 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.

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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

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.)

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Atmospheric Rivers-Water Year 2021-drought-climate

Atmospheric Rivers Left California Mostly Dry in Water Year 2021

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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

Landfalling Atmospheric Rivers Increase in First Quarter of Water Year 2021 Over 2020

/in , , /by /Water News Networkby Ed Joyce Mentioned: San Diego County Water Authority

A Scripps Center for Western Weather and Water Extremes report shows that more atmospheric rivers have made landfall over the U.S. West Coast in the first four months of Water Year 2021 compared to the previous period in 2020.

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Landfalling Atmospheric Rivers Increase in First Quarter of Water Year 2021 Over 2020

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A Scripps Center for Western Weather and Water Extremes report shows that more atmospheric rivers have made landfall over the U.S. West Coast in the first four months of Water Year 2021 compared to the previous period in 2020.

The four months of Water Year 2021 experienced a total of 35 landfalling ARs over the U.S. West Coast, six more than the first four months of Water Year 2020, according to the CW3E quarter year summary released February 11.

Key takeaways from the CW3E update on atmospheric rivers

• The first four months of Water Year 2021 experienced a total of 35 landfalling ARs over the U.S. West Coast, 6 more than the first four months of Water Year 2020.
• Water Year 2021 also experienced more than twice as many strong or greater ARs (14) compared to Water Year 2020 (6).
• While Water Year 2021 saw more ARs in its first 4 months compared to Water Year 2020, a large majority of those ARs were
strongest over the Pacific Northwest (Oregon and Washington).
• The average landfall latitude thus far in Water Year 2021 was 45.9°N compared to 43.9°N during the first half of Water Year 2020.
• The lack of landfalling ARs over Southern California and Baja California has resulted in much drier conditions over the southwestern U.S. compared to WY 2020.

CW3E-Atmospheric Rivers-Water Year 2021

The four months of Water Year 2021 experienced a total of 35 landfalling ARs over the U.S. West Coast, six more than the first four months of Water Year 2020. Graphic: Center for Western Weather and Water Extremes

Distribution of Landfalling Atmospheric Rivers over the U.S. West Coast During Water Year 2021: Quarter Year Summary

Atmospheric River-NOAA-WNN-CW3E

A partnership with the San Diego County Water Authority and the Scripps Institution of Oceanography at UC San Diego seeks to optimize water management to better predict atmospheric rivers before, during, and after those seasonal storms.

In August 2020, Scripps Center for Western Weather and Water Extremes (CW3E) launched the Water Affiliates Group, which brings together cutting-edge science and hands-on water industry experience to enhance reservoir operations in light of the changing climate. The Water Authority has a long-running alliance with Scripps and is among six founding water agencies statewide.

CW3E and its partners will share and support best practices in forecast-informed reservoir operations, increase research around atmospheric rivers and droughts, and develop strategies for mitigating flood risk and increasing water supply reliability.

Atmospheric Rivers-CW3E-water supply

The above image, from the EOS article, is a depiction of an atmospheric river, interacting with West Coast mountains and a midlatitude cyclone over the northeast Pacific on 5 February 2015. This image provides an example of approximate locations of associated tropical moisture exports and a warm conveyor belt (WCB). Graphic: Adapted from NOAA/ESRL Physical Sciences Division via CW3E

Scientists Use New Methods to Better Forecast Atmospheric Rivers

/in , /by /Sierra Nevada Allyby Scott King

Earlier this year, the Center for Western Weather and Water Extremes launched a new sub-seasonal to seasonal forecast product to better predict the influence atmospheric rivers will have on the Western United States. Better and more accurate forecasting tools for atmospheric rivers are critical for a number of community uses, including water management, agriculture, insurance and commodities trading, to name a few.

The demand for better atmospheric forecasting tools has facilitated the development of the new S2S forecasting products launched by CW3E this year.

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