We are under a La Niña watch, with NOAA projecting a 66% chance of development between September-November and 74% between November-January. 

Historically, La Niña events are associated with drier conditions in California, at times leading to severe droughts and unprecedented water restrictions, as witnessed through 2020-2022. 

But the story doesn’t end there

La Niña’s impact on precipitation is more complex and less predictable than it may seem.

For example, in the 2022-23 water year, despite La Niña conditions similar to those in previous dry years, California experienced above-normal precipitation. 

Even more intriguing, the 2016-17 water year, the wettest on record for California, also occurred during a weak La Niña. 

This variability highlights the challenge of predicting California’s weather based solely on La Niña or El Niño patterns.

Recent research by Dr. Jiang of UCLA emphasizes that sea surface temperatures explain only about 25% of the year-to-year variability in California’s precipitation.

The remaining 75% is influenced by complex atmospheric circulation patterns independent of ENSO (El Niño-Southern Oscillation) phases. 

This underscores the need for more advanced forecasting tools that go beyond traditional methods.

At Weather Tools, our California Annual Precipitation (CAP) forecast offers a unique solution. 

Our proprietary model doesn’t rely on historical climate patterns but instead focuses on a comprehensive approach that has consistently delivered accurate water year precipitation forecasts for eight consecutive years, regardless of climate forcing.

Additionally, the CAP model is the primary input in our newest product- a water year inflow forecast for 19 of California's major reservoirs, providing critical data to water managers who need to make informed decisions about water storage and allocation.

As we transition from the El Niño-dominated 2023-24 water year to a likely La Niña-influenced 2024-25, it’s crucial to be prepared. 

The CAP and inflow forecasts ensure you have the tools to navigate the complexities of seasonal weather patterns, helping you stay ahead—whether the outcome is wet or dry.

If you’d like to know more about our forecasts, email me at rob@weathertools.org or call 530-774-5475.