Looks like on Thursday, December 15th there was a Google search algorithm shift. We have some chatter on social media and in the WebmasterWorld forums. It seems like a significant one, but I am hoping this is just a bug or something and that Google did not push anything massive a week or so away from the holidays.
Here are some of the comments from the thread:
Google Dance… again…. sad
A new Google Update might be underway. Let’s wait and see happy!
The quality of organic was a lot better in the last 4 days but not so much today a few hours gap in orders
The tools are on fire, here are some screen shots: