Lake Tahoe snowpack measures 3% of average for May 1; Statewide stations at 37% of average

SOUTH LAKE TAHOE, Calif. – The fifth and final snow measurement of the year at Phillips Station took place Thursday, and results were very slim. The team from the Department of Water Resources (DWR) measured 1.5 inches of snow with a snow water equivalent (SWE) of 0.5 inches which is three percent of average for May 1.

The SWE measures the amount of water contained in the snowpack, providing a more accurate forecast of spring runoff than snow depth alone.

The meadow at the corner of US50 and Sierra-at-Tahoe Road, the normal location for the snow surveys, had very few patches of snow when DWR arrived. Sean de Guzman, chief of DWR’s Snow Survey and Water Supply Forecast Section, said the 130 electronic snow sensors scattered throughout the state indicate that the statewide snowpack’s water equivalent is 8.4 inches or 37 percent of the May average. He said Phillips Station is in a very exposed and sunny spot which allows for an expedited snow melt.

Today's readings will help hydrologists forecast spring and summer snowmelt runoff into rivers and reservoirs.

California’s weather variability has been on full display this water year. Guzman said the measure Thursday was a perfect example of how much not only snow years can differ, but also months within a single year. Phillips started off the season on Oct. 1 with dry conditions, then moved to a December that was 120 percent of average, then dry January and February with heavy snow in March lead to the snowpack peaking at just 66 percent of average on April.

“March and April storms brought needed snow to the Sierras, with the snowpack reaching its peak on April 9, however those gains were not nearly enough to offset a very dry January and February,” said Sean de Guzman, chief of DWR’s Snow Survey and Water Supply Forecast Section. “The last two weeks have seen increased temperatures leading to a rapid reduction of the snowpack. Snowmelt runoff into the reservoirs is forecasted to be below average.”

In normal years, the snowpack supplies about 30 percent of California’s water needs as it melts in the spring and early summer. The greater the snow water equivalent the greater the likelihood California’s reservoirs will receive ample runoff to meet the state’s water demand in the summer and fall.

The state’s six largest reservoirs currently hold between 83 percent (San Luis) and 126 percent (Melones) of their historical averages for this date. Lake Shasta, California’s largest surface reservoir, is 94 percent of its historical average and sits at 81 percent of capacity.