CNN CNN Newsroom Live September 16, 2015 04:14:00
Tuesday, this was the scene in hugher elevations. some snow showers at least begin to come in. and john, when you think about the observations, as far as the sierra snow pack, 30% of california's water comes in this snowfall. actually looking at tree ring observation. rainy seasons, typically the tree rings with farther apart. dry seasons, they're very compact. researchers looked at about 1,500 blue oak trees and they found out the last time the tree rings were this compacted together was about the year 1500. so over 500 years ago. and tree ring observation, when it comes to moisture has a ver...
Source: archive.org