Satellite images of the northern portion of California's Sierra Nevada acquired on March 24 in 2013 and 2014 show how much snowpack has shrunk. In the image from 2014, the scar from the Rim Fire is clearly visible. (Source: NASA) When surveyors for California's Department of Water Resources skied back down from sites high in California's Sierra Nevada range yesterday, they brought sobering news: Although late-season storms have boosted the snowpack, it is still shockingly below average as the melt season looms. According to a DWR report issued yesterday, the water content of the snowpack is only 32 percent of average for this time of year — which is when it typically reaches its peak and then melts off. This situation, combined with California's minimal rainfall, means the state faces serious water shortages and a high risk of wildfire as the summer looms. The animation above shows the snowpack in the northern part of the range on March 24 of 2013 and 2014. It consists of images captured by NASA's Aqua satellite. The big lake in the upper center is Lake Tahoe. The smaller, greenish lake in the lower right corner is Mono Lake. To the west of Mono Lake, on the other side of the Sierra, I've marked the location of the Rim Fire. The blaze began on August 17, 2013 and went on to consume 257,314 acres. The brown scar it has left is clearly visible in the satellite image. Will we see more fires like this as the warm season takes hold? As you contemplate that question, look for the small bluish plume of smoke faintly visible in the upper left of the 2014 image...