The Washington Post published a story today based on a study by the American Geophysical Union that explores the return period of the latest drought in California. The study, based on tree ring analysis, shows that the current exceptional drought is the worst in about 1200 years based on temperature and precipitation reconstructions. You can read the story here. The study also showed that about 44 percent of droughts that lasted 3 years went on to a fourth or more year. This week’s rains will be beneficial but are far short of what is needed to end this terrible drought.