Over the past two days I have been closely monitoring earthquake data and have noticed an extra-ordinary amount of cluster earthquakes, all over the world, but more importantly (to me) over Alaska, California and other parts of the US. History shows us that before major seismic activities cluster earthquakes can mark the beginning of a major event.
Full disclaimer: I'm no seismologist, but it would not surprise me if 'the big one' is coming; potentially beginning on the 21st (if not sooner) culminating in many large events that will not be limited to earthquakes; but may also include the eruption of Yosemite, Mt. Shasta, and other dormant volcanoes.
Update
I found this article about Mount Lo 'going silent' after erupting from being dormant for over 250 years.