Search appearances drop, search traffic increases ... how to interpret?

[Gavin.Atkinson]

I've just been comparing search appearances in Google Webmaster Tools with organic search traffic from Google and found that the two do not correspond at all. Why would this be?

GWT says my appearances in search crash-dived around the second week of September (does this correspond with a Google algorithm update?), but my organic search data in Google Analytics for the same time period shows that search visits actually increased.

Anyone else seeing anomalies like this?

525f2de7c58cc2-09483641 525f2e345acdf1-83344837