Around the start of each year, California water officials make a big show out of measuring the Sierra Nevada snowpack for reporters. Tuesday’s measurement before a throng of cameras was fairly bleak: Water content in the snowpack stood at just 53 percent of average, about a third as much water as the same time last year at that site. But as snowflakes drifted down, Frank Gehrke, director of snow surveys for the Department of Water Resources, struck a positive tone after taking the state’s first official manual snowpack reading of 2017 near Echo Summit.