Sonoma Water Reaches New Milestone For Regional Weather Forecast System

Sonoma Water, the County agency that delivers water to over 600,000 people, has reached a new radar milestone in its AQPI Project thanks to a powerful federal, state and regional partnership. Partners include federal National Oceanic and Atmospheric Administration, state Department of Water Resources, universities including Colorado State’s Cooperative Institute for Research in the Atmosphere, and Scripps Center for Western Weather and Water Extremes, and local water agency partners led by Sonoma Water.

• Five X-Band Radars around the Bay: as of this month, there are now five X-Band radars keeping watch over the Bay Area. These information-gap filling radars will track winter storms, including large atmospheric rivers, as they move into the Bay Area.
• Sawyer Ridge site: the newest addition on top of Sawyer Ridge in San Mateo County with views over the Bay and the Peninsula is the newest radar, deployed in July 2025; all equipment is expected to be ready before the rainy season starts.
• Why it matters: in 2024, throughout the United States, there were 27 confirmed weather/climate disaster events with losses exceeding $1 billion each. (NOAA: www.ncei.noaa.gov/access/billions) The new radars and the data communications systems that link the radar will provide better information more quickly to Bay Area water agencies and other storm watchers. The time savings and better data give communities more time to prepare for potential problems.
• Filling the gaps: standard weather radars often can’t “see” well over California’s mountains, where the heaviest rain often falls. AQPI’s radars provide a clearer picture.
• Protecting people and infrastructure: better data helps manage reservoirs, protect neighborhoods from flooding, operate stormwater systems, and guide emergency response.
• Part of a bigger picture: AQPI combines radar data, rain and stream gauges, storm forecasts and coastal flood modeling to keep the region safer and more resilient.
• Coming soon: the largest radar to be added to the system, a C-Band Radar to be installed in Marin County. This radar will “see” from the Pacific all the way to the middle of San Francisco Bay.
• When complete: AQPI will cover most Bay Area watersheds, with additional radars feeding into the system for even better coverage.

To learn more about AQPI, CLICK HERE