Sierra snowpack's water content Is 53% below average

South Lake Tahoe, Calif. - The weekend's heavy snowfall didn't do enough to bring good news during Tuesday's monthly manual snowpack survey at Phillips Station.

Frank Gehrke, chief of the California Cooperative Snow Surveys Program, led a media tour on January 3, 2017 to their normal spot near the turnoff to Sierra-at-Tahoe and found a snow water equivalent of six inches, which is 5.3 inches less that the average early-January total of 11.3 inches, 53 percent of normal.

The snow water equivalence is the depth of water that theoretically would result if the entire snowpack melted instantaneously. It is more important than depth as it shows water purveyors how much water can be expected to come out of the Sierra and fill up the state's reservoirs.

Since 1964, Department of Water Resources (DWR) has measured the snowpack at the same spot. (View all readings since 1964 here). From 1941 to 1963 snowpack was measured at the end of the wet season, and since 1964 it has been done monthly during the winter.

Percent of January 1 Average since 2002
2002..162%
2003..162%
2004..142%
2005..159%
2006..117%
2007..61%
2008..59%
2009..78%
2010..87%
2011..209%
2012..20%
2013..137%
2014..20%
2015..47%
2016..103%

More telling than a survey at a single location, however, are DWR’s electronic readings today from 105 stations scattered throughout the Sierra Nevada.

Measurements indicate the water content of the northern Sierra snowpack is 7.2 inches, 68 percent of the multi-decade average for the date. The central and southern Sierra readings are 7.4 inches (65 percent of average) and 6.6 inches (73 percent of average) respectively. Statewide, the snowpack holds 7.2 inches of water equivalent, or 70 percent of the January 3 average.

January and February are two of California’s three historically wettest months, which means the readings taken today at Phillips during the winter’s firstsnow survey are a key starting point of information but don’t shed much light on how wet the wet season ultimately will be.

Gehrke said the January average "seems a little gloomy," but to not despair.

“Keep in mind,” he continued, “we had pretty much bare ground here about a week ago, with a few patches of snow. Most of the snow we measured today came down in the last couple days and is continuing to come down.”

The new storm entering the Lake Tahoe Basin Tuesday is predicted to bring 2-4 feet of snow at the survey location.

“That’s going to bolster the snowpack,” he said. “I can see us being potentially at average once that series of storms moves through. I think it’s a very encouraging start to the winter, and certainly we’ve had other winters when (Phillips) has been basically a bare field.”

State Climatologist Mike Anderson said about half of California’s annual rainfall occurs in December, January and February and about two-thirds of the annual total arrives during December through March. Total precipitation so far this water year, which began October 1, has been above average, but warm temperatures during storm events have tended to cause precipitation to fall as rain rather than snow in many mountain locations.

“We still have three historically wet months ahead of us,” Anderson said, “so there’s still time for the snowpack to build and improve before it begins to melt, which usually starts happening around April 1.”

Acting DWR Director Bill Croyle said above-average precipitation since the start of Water Year 2017 in October added significantly to storage in 154 reservoirs tracked by the Department. Croyle said DWR has estimated total storage at the end of December at 21.5 million acre-feet (MAF), 98 percent of the reservoirs’ historical average of 21.9 MAF on December 31.

The video in this story is provided by the California Department of Water Resources.