Alex Padilla U.S. Senator for California

WASHINGTON, D.C. — Today, U.S. Senators Alex Padilla (D-Calif.) and Lisa Murkowski (R-Alaska) announced bipartisan legislation that will reduce flood risks and bolster emergency preparedness by improving atmospheric river forecasting to more precisely predict the timing and location of these storms. The Improving Atmospheric River Forecasts Act would require the National Oceanic and Atmospheric Administration (NOAA) to establish a forecast improvement program within the National Weather Service.

The legislation was announced as major atmospheric river storms bring high winds and heavy rain and snowfall to California.

Atmospheric rivers — often described as “rivers in the sky” that are hundreds of miles wide and can carry water vapor equivalent to multiple Mississippi Rivers — cause more than 80 percent of flood damage across the West. Climate change will only make these storms increasingly catastrophic: by 2090, atmospheric rivers are expected to cost $2.3 to $3.2 billion in annual damages and increase in width by nearly 25 percent. Over 50 atmospheric rivers made landfall across the West Coast from October 1, 2023 to September 30, 2024.

“For the past several years, California communities have witnessed firsthand the ongoing threat of destructive flooding caused by increasingly intense and frequent atmospheric river storms,” said Senator Padilla. “California has led the way in improving our understanding of these storms, and this bipartisan bill will strengthen forecasts to reduce flood risks while bolstering our water supply and drought resilience.”

“With greater frequency, we are seeing that atmospheric rivers instill dangerous climate conditions that pose deadly threats to Alaska communities,” said Senator Murkowski. “While there are numerous atmospheric river observatories in the Lower 48, none are in Alaska. This bill ensures that all states along the West coast, including Alaska, have at least one atmospheric river observatory. Along with improved modeling, data collection, and risk communication, this legislation will help protect our communities and ultimately save lives across Alaska.” 

“Atmospheric rivers are responsible for 30-50% of annual precipitation along the western U.S. and cause the majority of the flooding, with more than $1 billion in annual average flood damage in the western 11 states,” said Marty Ralph, Founding Director of the Center for Western Weather and Water Extremes at UC San Diego’s Scripps Institution of Oceanography. “The introduction of this act is critically important to advance forecasts of atmospheric rivers to enable more flexible and resilient water management, improved warning around flooding and overall improvements to public safety. It will also enhance the opportunities for reservoir operators to safely implement Forecast-Informed Reservoir Operations (FIRO) at more reservoirs to save additional water after a storm for the dry summer, or release it to mitigate flood risk if an AR storm is predicted in the next few days.”

Specifically, the Improving Atmospheric River Forecasts Act would direct NOAA to establish a standalone atmospheric river forecast improvement program that would:

• Develop accurate, effective, and actionable storm forecasts and warnings in collaboration with public and private partners across the weather forecasting sectors;
• Evaluate innovative observation tools and emerging technologies to improve atmospheric river analysis, modeling, forecasts, and warnings;
• Authorize NOAA to procure equipment, aircraft, and personnel contracts to fully monitor atmospheric river events each winter; and
• Improve atmospheric river hazard communication.

The Improving Atmospheric River Forecasts Act is endorsed by the Association of California Water Agencies, Association of Metropolitan Water Agencies, Bay Planning Coalition, Central Valley Flood Protection Board, Contra Costa Water District, Covington Water District, Irvine Ranch Water District, Kings River Conservation District, the National Association of Flood and Stormwater Management Agencies, Orange County Water District, Pajaro Regional Flood Management Agency, San Bernardino Valley Municipal Water District, Sacramento Area Flood Control Agency, San Diego County Water Authority, San Mateo County Flood and Sea Level Rise Resiliency District, Santa Clarita Valley Water Agency, Scripps Institution of Oceanography, San Francisco Public Utilities Commission, Sofar Ocean Technologies, Solano County Water Agency, Sonoma Water, Union Sanitary District, Valley Water, WindBorne Systems, and Yuba Water.

Senator Padilla has fought consistently for California communities devastated by atmospheric river flooding. Last year, Padilla urged the Biden Administration to prioritize sustained federal investment in the Pajaro River Flood Risk Management Project to protect disadvantaged communities along the central coast of California. Padilla also introduced the Atmospheric Rivers Reconnaissance, Observation and Warning (ARROW) Act to bolster West Coast atmospheric river forecasting, which was passed into law as part of the National Defense Authorization Act (NDAA) for Fiscal Year 2024.

Padilla has also championed funding for programs such as the Forecast-Informed Reservoir Operations (FIRO) to improve U.S. Army Corps of Engineers reservoir operations to increase water conservation and reliability at Lake Sonoma and Prado Dam, for example, while maintaining flood control and enhanced public safety during extreme precipitation events.

Full text of the bill is available here.

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