Sacramento, CA – Will Northern California see a wet, snow-heavy winter—or another season of uncertainty for water supplies? The National Weather Service’s (NWS) preliminary outlook for Winter 2025–26 shows equal chances of above, below, or near-normal snowfall and precipitation across the region, leaving Sierra snowpack and storm risks in question.
According to the Climate Prediction Center’s September 25 report, a weak La Niña is expected this fall before fading into ENSO-neutral conditions this winter. That transition tends to create volatile outcomes for California, where storm track and Pacific jet stream patterns largely determine precipitation.
“Predictability is very low right now,” forecasters said, pointing out that atmospheric rivers and short-term Pacific oscillations could tip the balance between drought relief and a drier season.
What It Means for Northern California
- Sierra Nevada (Lake Tahoe, Yosemite, Mammoth Lakes): Remains the most critical area to watch, as heavy snowpack here fuels water supplies. ENSO-neutral winters have historically delivered both record snow years and disappointing dry ones.
- Sacramento Valley & Foothills: Vulnerable to atmospheric river events, which can bring flooding rains if storm tracks align with subtropical moisture.
- Northern Coast & Shasta region: Often see significant winter rainfall under stormier Pacific patterns but can also dry out quickly in weaker setups.
Water Supply & Risk Factors
Snowpack in the Sierra Nevada provides about one-third of California’s water supply, making the outcome of this winter critical for farmers, reservoirs, and urban centers alike. Even if totals average out near normal, flooding and mudslide risks increase sharply during strong storm bursts.
Preparing for the Season
The bottom line: Northern California faces a 50/50 outlook heading into Winter 2025–26. While there’s no guarantee of a drought-busting year, the potential for heavy Sierra snow, atmospheric rivers, and flooding remains very much alive.
Meteorologists warn that a warmer-than-average fall could give way to sudden December storms, creating early-season challenges for mountain passes and reservoirs.
The official NOAA winter outlook will be released October 16, which may provide sharper guidance on how Northern California’s storm season could unfold.
