La Niña, Tahoe Snow & California’s Water Supply
Correction and revision — September 13, 2026. An earlier version described California’s 2010–11 winter as dry. That was wrong. It also included drought, reservoir and snowfall figures without adequate dates or support. Those figures have been removed.
La Niña gets people talking about winter before the first chair spins. Fair enough. We all want to know what is coming. But the name of an ocean pattern does not tell us how many powder days Tahoe will get.
What La Niña tells us
La Niña is the cooler phase of the El Niño–Southern Oscillation, a pattern involving the tropical Pacific and the atmosphere. It can shift the odds for seasonal weather. NOAA describes a tendency toward drier winters in Southern California, with a less consistent signal farther north. That leaves plenty of room for a Tahoe winter to take its own path. Read NOAA’s explanation.
The 2010–11 correction
On March 30, 2011, California reported that the water held in its mountain snowpack stood at 165% of the April 1 full-season average. The state also ended its drought declaration. That is a direct counterexample to the earlier claim that the 2010–11 La Niña produced a dry California winter. See the state’s March 2011 report.
NOAA also documented a remarkably wet California winter during the weak 2016–17 La Niña. The seasonal tendency is useful background. It is not a promise about every storm or every winter.
Snowfall and water content are different numbers
New snowfall tells us how much snow fell at a reporting site. Snow water equivalent tells us how much water that snowpack holds. A resort’s season total, one snow plot and the statewide snowpack are different measurements. Keep the location, date, units and comparison period with every number. DWR’s snow surveys explain the statewide measurements.
When I read the winter ahead, I want the ocean outlook, the storm track, the cold air and the local observations in the same conversation. Big precipitation colors get our attention. The rain-and-snow split is what matters when those storms reach the Sierra.
Keep the current report close
This article began as a 2024 discussion. Today’s conditions belong with today’s sources. Use Coop’s Lake Tahoe weather page for the current forecast and California Water Watch for dated water conditions.
I care about the snow under our skis and the water that carries us through the rest of the year. Read the measurements. Keep the uncertainty in view. Stay’nThirsty for POW.
Coop
