SB-599
Natural Resources & Water

Atmospheric rivers: research: forecasting methods: experimental tools.

Introduced
CA
2025-2026 Regular Session
0
0
Track

Key Takeaways

  • Requires the Department of Water Resources to use experimental tools for forecasting atmospheric rivers.
  • Mandates improved reservoir operations to enhance flood protection and water capture.
  • Establishes forecasting periods from 2 weeks to 6 months to predict atmospheric river impacts.
  • Requires sharing of forecast data with federal, state, and local agencies.
10% progression
Bill has been formally introduced and read for the first time in its house of origin (2/20/2025)
Probability of Passing
We're working on it! Check back later.

Summary

Senator Caballero's atmospheric river forecasting legislation expands California's water management capabilities by requiring the Department of Water Resources to incorporate experimental seasonal and subseasonal forecasting tools into its existing research program. The bill adds these longer-range prediction requirements to the department's Atmospheric Rivers Research and Forecast Improvement Program, which develops methods to anticipate and respond to these concentrated bands of Pacific moisture that deliver up to half of California's annual precipitation.

The legislation directs the department to apply these extended forecasts, ranging from two weeks to six months, to reservoir operations and flood control decisions. Under the bill, information from these experimental forecasting tools must be shared with federal, state and local agencies to support coordinated water management. The department would continue using forecast data to adjust reservoir operations for capturing atmospheric river flows while maintaining flood protection capacity.

This measure builds upon California's current atmospheric river monitoring system, which the bill's findings indicate has already demonstrated improved accuracy. According to the legislative findings, five-day forecasts in 2020 achieved greater precision than four-day predictions from 2017. The findings also note that atmospheric rivers have caused 94 percent of California's flood damages, averaging $620 million annually, while recent winter storms in 2022-2023 resulted in $30 billion in damages across 40 counties.

Get Involved

Act Now!

This bill was recently introduced. Email the authors to let them know what you think about it.

Introduced By

Anna Caballero
Anna CaballeroD
California State Senator

Community Outlook

No votes yet
Positive
0%
Negative
0%

Key Dates

Next Step
Referred to the Senate Standing Committee on Natural Resources and Water
Next Step
Senate Committee
Referred to the Senate Standing Committee on Natural Resources and Water
Hearing scheduled for , State Capitol, Room 113
Introduced. Read first time. To Com. on RLS. for assignment. To print.
Senate Floor
Introduced. Read first time. To Com. on RLS. for assignment. To print.
Introduced. Read first time. To Com. on RLS. for assignment. To print.

Relevant Contacts

Profile
Anna CaballeroD
Senator
Bill Author
Not Contacted
Not Contacted
Profile
Shannon GroveR
Senator
Committee Member
Not Contacted
Not Contacted
Profile
Benjamin AllenD
Senator
Committee Member
Not Contacted
Not Contacted
Profile
Henry SternD
Senator
Committee Member
Not Contacted
Not Contacted
Profile
Monique LimonD
Senator
Committee Member
Not Contacted
Not Contacted
0 of 8 row(s) selected.
Page 1 of 2
Select All Legislators
Profile
Anna CaballeroD
Senator
Bill Author
Profile
Shannon GroveR
Senator
Committee Member
Profile
Benjamin AllenD
Senator
Committee Member
Profile
Henry SternD
Senator
Committee Member
Profile
Monique LimonD
Senator
Committee Member
Profile
Melissa HurtadoD
Senator
Committee Member
Profile
Kelly SeyartoR
Senator
Committee Member
Profile
John LairdD
Senator
Committee Member

Key Takeaways

  • Requires the Department of Water Resources to use experimental tools for forecasting atmospheric rivers.
  • Mandates improved reservoir operations to enhance flood protection and water capture.
  • Establishes forecasting periods from 2 weeks to 6 months to predict atmospheric river impacts.
  • Requires sharing of forecast data with federal, state, and local agencies.

Get Involved

Act Now!

This bill was recently introduced. Email the authors to let them know what you think about it.

Introduced By

Anna Caballero
Anna CaballeroD
California State Senator

Summary

Senator Caballero's atmospheric river forecasting legislation expands California's water management capabilities by requiring the Department of Water Resources to incorporate experimental seasonal and subseasonal forecasting tools into its existing research program. The bill adds these longer-range prediction requirements to the department's Atmospheric Rivers Research and Forecast Improvement Program, which develops methods to anticipate and respond to these concentrated bands of Pacific moisture that deliver up to half of California's annual precipitation.

The legislation directs the department to apply these extended forecasts, ranging from two weeks to six months, to reservoir operations and flood control decisions. Under the bill, information from these experimental forecasting tools must be shared with federal, state and local agencies to support coordinated water management. The department would continue using forecast data to adjust reservoir operations for capturing atmospheric river flows while maintaining flood protection capacity.

This measure builds upon California's current atmospheric river monitoring system, which the bill's findings indicate has already demonstrated improved accuracy. According to the legislative findings, five-day forecasts in 2020 achieved greater precision than four-day predictions from 2017. The findings also note that atmospheric rivers have caused 94 percent of California's flood damages, averaging $620 million annually, while recent winter storms in 2022-2023 resulted in $30 billion in damages across 40 counties.

10% progression
Bill has been formally introduced and read for the first time in its house of origin (2/20/2025)
Probability of Passing
We're working on it! Check back later.

Key Dates

Next Step
Referred to the Senate Standing Committee on Natural Resources and Water
Next Step
Senate Committee
Referred to the Senate Standing Committee on Natural Resources and Water
Hearing scheduled for , State Capitol, Room 113
Introduced. Read first time. To Com. on RLS. for assignment. To print.
Senate Floor
Introduced. Read first time. To Com. on RLS. for assignment. To print.
Introduced. Read first time. To Com. on RLS. for assignment. To print.

Community Outlook

No votes yet
Positive
0%
Negative
0%

Relevant Contacts

Profile
Anna CaballeroD
Senator
Bill Author
Not Contacted
Not Contacted
Profile
Shannon GroveR
Senator
Committee Member
Not Contacted
Not Contacted
Profile
Benjamin AllenD
Senator
Committee Member
Not Contacted
Not Contacted
Profile
Henry SternD
Senator
Committee Member
Not Contacted
Not Contacted
Profile
Monique LimonD
Senator
Committee Member
Not Contacted
Not Contacted
0 of 8 row(s) selected.
Page 1 of 2
Select All Legislators
Profile
Anna CaballeroD
Senator
Bill Author
Profile
Shannon GroveR
Senator
Committee Member
Profile
Benjamin AllenD
Senator
Committee Member
Profile
Henry SternD
Senator
Committee Member
Profile
Monique LimonD
Senator
Committee Member
Profile
Melissa HurtadoD
Senator
Committee Member
Profile
Kelly SeyartoR
Senator
Committee Member
Profile
John LairdD
Senator
Committee Member