An overarching theme of my research is to build understanding of the phenomena and mechanisms linking weather and climate, focusing especially on high impact phenomena such as heat waves, droughts, extratropical cyclones and blocking. The ultimate goal of this research is to improve NOAA's weather and climate predictions and services. I am a Fellow of the American Meteorological Society and of the University of Colorado/CIRES, and am also Division Director for the CIRES Weather and Climate Dynamics Division. I currently serve on the WMO World Weather Research Program Joint Scientific Committee, which provides the highest level of scientific review and guidance for international weather research coordinated through the WMO/WWRP. Previously, I served as the co-chair of the inter-agency working group on Climate Variability and Change for the U.S. Global Change Research Program, and as a member on the U.S. delegation for the IPCC Working Group I Report "Climate Change 2007: The Physical Science Basis".