Extreme drought, the second-highest level of drought, has been nearly eliminated in the state of California in the wake of storms caused by atmospheric rivers slamming the state over the last several weeks.The week prior, parts of California and Nevada that were previously in exceptional drought status no longer qualified for the highest level of concern due to the extra moisture.The rain is helpful, but snowpack is even more critical -- even preferable -- because it melts slowly and is better absorbed by the ground and also later contributes to the "water bank" for the spring and summer, Nate Stephenson, a scientist emeritus at the U.S. Geological Survey's Western Ecological Research Center, told ABC News.The moisture is likely staving off a mass die-off of trees in the state, experts told ABC News.The inundation so far is not helping the Colorado River Basin as much, the region that needs the most help -- including Lake Mead and Lake Powell -- because they are in the heart of a 22-year mega drought."