For the very keen, or technically inclined

Reanalysis Intercomparison and Observations

"Reanalyses.org is intended to be a place to provide researchers with help to obtain, read and analyze reanalysis datasets created by different climate and weather organizations. In addition, users have a place to carry out discussions about these reanalyses, how they compare with each other and with observations."

"Reanalysis is a scientific method for developing a comprehensive record of how weather and climate are changing over time. In it, observations and a numerical model that simulates one or more aspects of the Earth system are combined objectively to generate a synthesized estimate of the state of the system. A reanalysis typically extends over several decades or longer, and covers the entire globe from the Earth’s surface to well above the stratosphere. Reanalysis products are used extensively in climate research and services, including for monitoring and comparing current climate conditions with those of the past, identifying the causes of climate variations and change, and preparing climate predictions. Information derived from reanalyses is also being used increasingly in commercial and business applications in sectors such as energy, agriculture, water resources, and insurance."

http://reanalyses.org/

Realclimate article about this site and topic:
http://www.realclimate.org/index.php/archives/2011/07/reanalyses-r-us/