Series of December storms provides a good start to Sierra snowpack

By Elizabeth Larson | Jan. 3, 2020
Sean de Guzman, right, chief of the California Department of Water Resources Snow Surveys and Water Supply Forecasting Section, prepares to insert the long aluminum snow depth survey pole into the snow for the first media snow survey of the 2020 season on Thursday, January 2, 2020. The event was held at Phillips Station in the Sierra Nevada Mountains. Ramesh Gautum, chief of the California Cooperative Snow Surveys Program, and Lauren Miller, engineer for the DWR’s Snow Surveys and Water Supply Forecasting Section, help with the survey held approximately 90 miles east of Sacramento off Highway 50 in El Dorado County, California. Photo by Ken James/California Department of Water Resources.

NORTHERN CALIFORNIA – The Department of Water Resources on Thursday conducted the first manual snow survey of 2020 at Phillips Station.

The manual survey recorded 33.5 inches of snow depth and a snow water equivalent, or SWE, of 11 inches, which is 97 percent of average for this location.

The SWE measures the amount of water contained in the snowpack, which provides a more accurate forecast of spring runoff.

“While the series of cold weather storms in November and December has provided a good start to the 2020 snowpack, precipitation in Northern California is still below average for this time of year,” said DWR Director Karla Nemeth. “We must remember how variable California’s climate is and what a profound impact climate change has on our snowpack.”

More telling than a survey at a single location are DWR’s electronic readings from 130 stations scattered throughout the State. Measurements indicate that statewide, the snowpack’s SWE is 9.3 inches, or 90 percent of the Jan. 2 average.

“It’s still too early to predict what the remainder of the year will bring in terms of snowpack,” said Sean DeGuzman, chief of DWR’s Snow Surveys and Water Supply Forecasting Section. “Climate change is altering the balance of rain and snow in California. That is why it is important to maintain our measurements of the snowpack to document the change in addition to having critical information to forecast spring runoff.”

Sean de Guzman, right, chief of the California Department of Water Resources Snow Surveys and Water Supply Forecasting Section, conducts the first media snow survey of the 2020 season at Phillips Station in the Sierra Nevada Mountains on Thursday, January 2, 2020. Ramesh Gautum, chief of the California Cooperative Snow Surveys Program, and Lauren Miller, engineer for the DWR’s Snow Surveys and Water Supply Forecasting Section, help with the survey held approximately 90 miles east of Sacramento off Highway 50 in El Dorado County, California. Photo by Ken James/California Department of Water Resources.

California traditionally receives about 75 percent of its annual precipitation during December, January and February, with the bulk of this precipitation coming from atmospheric rivers.

Similar to last year, California experienced a dry start to this water year followed by cold, wet December storms that brought the state up to 74 percent of average annual precipitation for this time of year.

State officials said climate change is expected to lead to continued warming and fewer but more intense storms impacting the snowpack of the Sierra Nevada. These changes continue to impact the distribution of snow across elevations, its pattern of accumulation, and rate of melt.

DWR conducts five media-oriented snow surveys at Phillips Station each winter in January, February, March, April and, if necessary, May.

On average, the snowpack supplies about 30 percent of California’s water needs as it melts in the spring and early summer.

In related news, a snowpack measurement conducted Dec. 30 at Anthony Peak in the Mendocino National Forest’s Covelo Ranger District found snow at a depth of 17 inches with a density of 24 percent, compared to 25.5 inches and 43 percent density measured in January 2019.


Nearby mountain peaks are covered with snow near the Phillips Station meadow, where the California Department of Water Resources conducted its first media snow survey of the 2020 season at Phillips Station in the Sierra Nevada Mountains on Thursday, January 2, 2020. The survey site is approximately 90 miles east of Sacramento off Highway 50 in El Dorado County, California. Photo by Ken James/California Department of Water Resources.