I have been working on several US based clients in 2013. On one specific project I am working on which involves the following:
– Analysis of poor quality links.
– Manual removal of a large number of links in thousands.
– Large amount of links been disavowed in thousands.
– Building new high quality links.
– Reconsideration requests.
Now we have been pushing hard for several months, I noticed on the 13th July Moz Cast noted 87% flux on the SERP weather report.
This has resulted in a positive impact on the clients SERP position (see below)
Overall it could be a niche specific update or a wider update for sites based on July 13th.