In April 2025, the operators at Lake Mendocino in Sonoma County held more water behind the dam than traditional rule curves would have allowed. They could do that because the reservoir is equipped with Forecast-Informed Reservoir Operations, or FIRO, a system that uses real-time weather data to guide release decisions instead of relying on fixed seasonal schedules. A few hundred miles south, homeowners in the foothills above Los Angeles were still clearing ash from the devastating January 2025 fires when CAL FIRE notified them that their properties had been reclassified into Very High Fire Hazard Severity Zones. Both situations trace back to the same underlying problem: California’s climate is lurching between extremes so fast that the state’s water and fire infrastructure can barely keep up.
A forecasting system under pressure
The strain shows most clearly in how California predicts its water supply. Every spring, the Department of Water Resources publishes Bulletin 120, a forecast that blends snowpack measurements, short-range weather models, and decades of historical climate data to estimate how much runoff will flow into the state’s reservoirs through the summer. The system worked well enough when California’s wet and dry years followed roughly familiar patterns. That assumption broke down around water year 2023, when the state swung from severe drought to record precipitation in a matter of months.
DWR’s Snow Surveys and Water Supply Forecasting Unit has described this pattern as climate whiplash, and the agency has acknowledged that the rapid swings degrade the accuracy of models built on historical averages. When the past stops being a reliable guide, reservoir operators lose the lead time they depend on to balance two competing demands: holding enough water for the next drought while keeping enough space open to absorb the next flood.
To close that gap, the state has pushed two concrete upgrades. FIRO, first piloted at Lake Mendocino and since expanded to facilities including Prado Dam in San Bernardino County, lets managers incorporate atmospheric-river forecasts into release decisions days before a storm arrives. Alongside FIRO, DWR has expanded its stream gage network to capture faster-moving hydrological signals across the state. Both investments reflect an institutional admission: the infrastructure California built for a more predictable climate needs real-time intelligence to function safely in this one.
Fire risk redrawn after the January 2025 blazes
The January 2025 fires that tore through the Palisades and Eaton Canyon areas near Los Angeles offered a brutal illustration of what whiplash looks like on the ground. According to NOAA’s Climate.gov, the region had swung from record-wet conditions to record-dry conditions in a compressed timeframe. Heavy rains fueled dense vegetation growth; weeks of hot, dry Santa Ana winds then cured that vegetation into explosive fuel. Climate change and the tail end of an El Niño-to-La Niña transition both amplified the fire-weather setup…