The Department of Water Resources’ (DWR) first “official” snow survey at Phillips, a former post office, and stagecoach stop is largely ceremonial. The site is at an elevation of 6,800 feet. Frank Gehrke, the DWR employee who runs the survey, wore simple winter boots instead of coming in on cross-country skis, as he has done in the past.
When the measurements were finished, Gehrke reported the results, and they were dismal. There were just 1.3 inches (2.5 centimeters) of snow on average, and a “snow water content” of 0.4 inches. No matter how you look at the numbers, it still comes to only 3.0 percent of average for early January.
“We would like to have had more snow,” Grant Davis, the head of California’s DWR who had accompanied Gehrke, told news crews gathered in the meadow, reports ABC News. “It’s early,” Davis said. “We’re obviously hopeful there will be more snow the next time we come out here.”
Measuring snowpack using “snow pillows”
The results of the ceremonial measurement at Phillips is not typical of how the state is faring. Most of the Sierra Nevada snowpack right now is about 2.6 inches, or 24 percent of normal, based on electronic readings from “snow pillows” scattered throughout the mountains.
Snow pillows were first used in the mid-1960s at Mt. Hood, Oregon. The pillows measure the water equivalent of the snowpack based on hydrostatic pressure created by overlying snow. Any discrepancy due to bridging is minimized by the large dimension of the pillow, typically 3 meters (120 inches) square.
California has 103 stations scattered throughout the Sierra Nevada. California traditionally receives about half of its annual precipitation during December, January, and February, with the bulk of this precipitation coming from atmospheric rivers (ARs).
Davis and Gehrke both expressed hope that the rest of the winter will bring better results. “We’re very early in the season,” Gehrke said. “We have had very dramatic turnarounds.”
Davis added, “I’m not going to say the anxiety level is any higher than normal.”
California’s winter weather can be fickle
California’s wettest months are December through February, so there’s still time for Mother Nature to build her mountain “reservoir” and eventually provide the runoff California needs when it melts, according to the DWR website.
Davis noted that forecasting accuracy falls off dramatically after just a week or 10 days into the future. “Current technology and computer modeling can tell us what our weather might be weeks into the future, but we’re essentially blind to what the weather will be beyond the two-week mark,” he said. “That’s why we are putting in so much effort to improving medium- and long-range modeling.”
Climate change is having a bigger role in changing the mountain snowfall in California. Traditionally, as much as 60 percent of the state’s water supply starts out each year as snowfall in the Sierra Nevada’s. This makes manual and electronic snowpack measurements all the more crucial for conservation and water usage.
