Stuart Staniford:
Terrifying Drought Projections
On the projections of the Palmer Drought Severity Index: I was pretty freaked out by the paper. This post covers PDSI at a very basic level, and discusses the projections.
Recent History of Drought vs Models
This post looked at the somewhat imperfect fit between climate models and drought data for recent history.
Extracting Signal From Drought Noise
This post extracted the global warming signal and the El-Nino signal from the drought data.