Reuters: Snow levels atop California's Sierra Nevada mountains, key indicators of how much water will be available for drought-stricken farms, residents and wildlife this summer, remained precariously low despite recent storms, officials said Tuesday. The snowpack, which melts in the spring and feeds streams and reservoirs throughout the state, has just a third of the amount of water it normally contains this time of year, said Mark Cowin, director of the state Department of Water Resources. "We're already...