The US CLIVAR Extremes Working Group was formed in 2012 to evaluate whether current climate models produce extremes for the right reasons and whether they can be used for predicting and projecting short-term extremes in temperature and precipitation over North America. The WG concluded their activities in 2015.

Their scientific objectives include:

• Assess and synthesize existing knowledge base on the links between Large Scale Circulation Patterns (LSCP) and short term temperature and precipitation extremes.
• Identify key questions and knowledge gaps.
• Establish a methodology and research protocols for using the LSCP approach to analyzing extremes in observations and model output.
• Provide a preliminary assessment of the ability of current models to reproduce the correct relationship between extremes and LSCs for North America.