San Mateo County Puts Atmospheric River Science to Work for More Lead Time Before Winter Storms

Atmospheric River Emergency System (ARES) gives earlier, local warning of severe storms as Rep. Mullin announces READI Act to strengthen phone alerts

REDWOOD CITY, CA, UNITED STATES, October 30, 2026 /EINPresswire.com/ -- San Mateo County Emergency Management (SMC EM) today launched ARES, the Atmospheric River Emergency System, a partnership with the Center for Western Weather and Water Extremes (CW3E) at UC San Diego’s Scripps Institution of Oceanography. ARES pairs CW3E’s storm science with SMC EM’s emergency operations to give the county more lead time and a neighborhood-level view of atmospheric river storms, so crews can stage, residents can be warned, and resources can be in place before the storms peak.

ARES brings together local radar and rain gauge data from the county’s coast, measurements taken inside storms as they form over the Pacific, and what the county knows about conditions on the ground, so emergency managers can pinpoint which neighborhoods are likely to be hit hardest. The county is already using that data this season, and it is finalizing a full ARES dashboard. At today’s event, emergency managers replayed AQPI radar from previous severe storms and previewed the ARES dashboard. Throughout each storm, county emergency management leadership and the CW3E team check what they see on the ground, in the air, and in weather forecast models, so decisions rest on verified data. ARES works alongside the National Weather Service, adding local detail to its forecasts.

Supervisor Ray Mueller, Vice President of the Board of Supervisors and Chair of the Emergency Services Council, announced the partnership in the Board of Supervisors Chambers alongside Rep. Kevin Mullin, Rep. Sam Liccardo, Emergency Management Director Dr. Shruti Dhapodkar and CW3E Founding Director Dr. F. Martin Ralph.

“Every hour of warning is an hour to move crews, guide residents and send resources where they’re needed most before the water rises,” said Supervisor Mueller. “ARES gives that lead time to all 20 of our cities and 18 unincorporated areas, and this winter, lead time is what keeps people safe.”

The launch caps three days Dr. Ralph spent in San Mateo County learning alongside the people who will act on this science. He met with county executives and members of the Board of Supervisors, joined life science and private sector leaders at a Biocom California gathering, engaged with 100+ law, fire, EMS, and public information partners at the county's Compass Forum, and presented to elected officials from cities. Those sessions focused on understanding severe weather and practicing the response together.

“I’ve spent 30 years researching, flying into atmospheric rivers and building the tools to measure them, and this week I saw that science come full circle with the emergency managers who make the calls that save lives,” said Dr. Ralph. “With El Niño, coastal and tidal flooding is the greater concern this winter. Heavy rain is possible, not a guarantee, which is exactly why lead time matters.”

Proven science, delivered locally

ARES draws on the Advanced Quantitative Precipitation Information system, known as AQPI, developed by NOAA Research, Colorado State University's Cooperative Institute for Research in the Atmosphere, and CW3E to give nine Bay Area counties more accurate and timely warning of flooding from heavy rain. Its completed network of five X-band radars and one C-band radar covers most of the greater Bay Area, and one of those radars sits in San Mateo County, updating about every two minutes. AQPI was funded through a California Department of Water Resources grant and built on more than a decade of NOAA research on extreme precipitation in California.

During the press conference, Rep. Mullin also announced his new legislation, the Reliable Emergency Alert Delivery Integrity (READI) Act. The bill would direct the Federal Communications Commission to improve the Wireless Emergency Alerts (WEA) system, which authorities use to send geo-targeted notifications to cellphones. Past disasters such as the Los Angeles wildfires and Camp Mystic floods in Texas have highlighted failures in the system. The READI Act would establish performance goals for WEA around speed, coverage, and geographic targeting, and study the use of advanced translation technology for multilingual alerts.

“We need to be looking at both ends of a crisis: how to better forecast and predict where the impacts will land, and how we can ensure that information gets to the people at risk,” said Rep. Mullin. “ARES builds on decades of federal funding and provides essential, localized information for first responders. In California, we know all too well that seconds count during a crisis, and emergency alerts can truly make the difference between life and death. I’m introducing the READI Act because the federal government needs to improve the Wireless Emergency Alert system so that communities can trust they’ll receive timely and accurate information when they need it most.”

“Federal research could buy us critical hours before a storm hits our Coastside; preparation makes those hours count to save lives and livelihoods,” said Rep. Liccardo. “That’s why we’ve secured millions for flood protection on the Peninsula and Coastside, and why I introduced legislation like the Ounce of Prevention Act. The cost of preparation pales in comparison to the price of inaction.”

“The best science in the world is worthless if it doesn’t change what we do collectively,” said Dr. Dhapodkar. “ARES gives us the data, but we all need to take action, and that means every single one of us. We know communities that connect early and often are more resilient during a disaster, so have a conversation with your family this weekend and with your colleagues at work next week. Refresh your go bags and check your batteries. Know your flood risk at home and at work, and sign up for alerts at smcalert.info. Use the state’s directory of every county’s alert system (https://calalerts.org/) for anywhere else in the Bay Area you live, work, or travel. Small investments in connection and readiness now will make all the difference when this season is upon us.”

SMC Emergency Management is also encouraging every resident to be aware of this winter's peak high tide windows around Thanksgiving (Nov. 21 to 28), Christmas (Dec. 20 to 27), and mid to late January (Jan. 17-24) so they can plan.

Cari Guittard
SMC Emergency Management
+1 415-608-0806