COMPLETING THE FORECAST
Characterizing and Communicating Uncertainty for Better Decisions Using Weather and Climate Forecasts
THE NATIONAL ACADEMIES PRESS
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NOTICE: The project that is the subject of this report was approved by the Governing Board of the National Research Council, whose members are drawn from the councils of the National Academy of Sciences, the National Academy of Engineering, and the Institute of Medicine. The members of the committee responsible for the report were chosen for their special competences and with regard for appropriate balance.
Support for this project was provided by the National Oceanic and Atmospheric Administration under Contract No. DG133R04CQ0009, Task Order #3. Any opinions, findings, and conclusions, or recommendations expressed in this publication are those of the author(s) and do not necessarily reflect the views of the organizations or agencies that provided support for the project.
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THE NATIONAL ACADEMIES
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COMMITTEE ON ESTIMATING AND COMMUNICATING UNCERTAINTY IN WEATHER AND CLIMATE FORECASTS
RAYMOND J. BAN (Chair),
The Weather Channel, Inc., Atlanta, Georgia
JOHN T. ANDREW,
California Department of Water Resources, Sacramento, California
BARBARA G. BROWN,
National Center for Atmospheric Research, Boulder, Colorado
DAVID CHANGNON,
Northern Illinois University, DeKalb, Illinois
KONSTANTINE GEORGAKAKOS,
Hydrologic Research Center, San Diego, California
JAMES HANSEN,
Massachusetts Institute of Technology, Cambridge
RONALD N. KEENER, JR.,
Duke Energy, Charlotte, North Carolina
UPMANU LALL,
Columbia University, New York
CLIFFORD F. MASS,
University of Washington, Seattle
REBECCA E. MORSS,
National Center for Atmospheric Research, Boulder, Colorado
ROBERT T. RYAN,
NBC4, Washington, DC
ELKE U. WEBER,
Columbia University, New York
NRC Staff
PAUL CUTLER, Study Director
LEAH PROBST, Research Associate
ROB GREENWAY, Senior Program Assistant
BOARD ON ATMOSPHERIC SCIENCES AND CLIMATE
ROBERT J. SERAFIN (Chair),
National Center for Atmospheric Research, Boulder, Colorado
M. JOAN ALEXANDER,
NorthWest Research Associates/CORA, Boulder, Colorado
FREDERICK R. ANDERSON,
McKenna Long & Aldridge LLP, Washington, DC
MICHAEL L. BENDER,
Princeton University, New Jersey
ROSINA M. BIERBAUM,
University of Michigan, Ann Arbor
MARY ANNE CARROLL,
University of Michigan, Ann Arbor
CAROL ANNE CLAYSON,
Florida State University, Tallahassee
WALTER F. DABBERDT,
Vaisala Inc., Boulder, Colorado
KERRY A. EMANUEL,
Massachusetts Institute of Technology, Cambridge
DENNIS L. HARTMANN,
University of Washington, Seattle
PETER R. LEAVITT,
Weather Information Inc., Newton, Massachusetts
JENNIFER A. LOGAN,
Harvard University, Cambridge, Massachusetts
VERNON R. MORRIS,
Howard University, Washington, DC
F. SHERWOOD ROWLAND,
University of California, Irvine
THOMAS H. VONDER HAAR,
Colorado State University/CIRA, Fort Collins
ROGER M. WAKIMOTO,
National Center for Atmospheric Research, Boulder, Colorado
Ex Officio Members
ANTONIO J. BUSALACCHI, JR.,
University of Maryland, College Park
ERIC F. WOOD,
Princeton University, New Jersey
NRC Staff
CHRIS ELFRING, Director
PAUL CUTLER, Senior Program Officer
AMANDA STAUDT, Senior Program Officer
IAN KRAUCUNAS, Associate Program Officer
CLAUDIA MENGELT, Associate Program Officer
LEAH PROBST, Research Associate
ELIZABETH A. GALINIS, Research Associate
ROB GREENWAY, Senior Program Assistant
DIANE GUSTAFSON, Administrative Coordinator
ANDREAS SOHRE, Financial Associate
Preface
Recognizing the opportunity to enhance the service it provides to the nation, the National Weather Service (NWS) commissioned the National Research Council (NRC) to form a committee to provide recommendations on how NWS can more effectively estimate and communicate uncertainty in weather and climate forecasts. This opportunity was highlighted in Recommendation 8 of the report Fair Weather: Effective Partnerships in Weather and Climate Forecasts (NRC, 2003a) and NWS desired more specific input in this area.
The committee was tasked with providing guidance on understanding and characterizing user needs for uncertainty information, suggesting improvements in current methods used to estimate and validate uncertainty products and recommending improvements in methods used to communicate uncertainty information. Since weather services in the United States are the result of an interdependent enterprise consisting of public, private, and academic assets, NWS also asked the committee to make recommendations consistent with an “enterprise” viewpoint.
At the very beginning of the study, the committee realized that an exhaustive look at the needs of users or user categories with regard to uncertainty information would be vastly beyond its time constraints and resources. Although several specific examples of user needs appear in the report (as requested in the charge), the overall thrust is to provide NWS with a template of how to effectively assess the unique needs of a very wide range of users. The psychology of decision-making processes is presented along with general paths that the enterprise can follow in providing useful input into decision-support systems. “Teaching how to fish versus catching a fish” is an appropriate analogy and is one that NWS used at the committee’s first meeting.
The committee met a total of five times between April 2005 and February 2006 and received broad and diverse input from specialists on topics ranging from probabilistic data generation, to product development, to user decision processes. The committee would like to thank all of those who provided their time and insight. The contributors are listed in Appendix B of the report.
Finally the committee thanks NWS personnel for all of the input they provided during the course of the study, including answers to our many questions and numerous and complete product summaries. In particular we thank Ed Johnson, Lee Anderson, and John Sokich for their prompt and complete responses.
Raymond J. Ban, Chair
Committee on Estimating and Communicating Uncertainty in Weather and Climate Forecasts
Acknowledgments
This report has been reviewed in draft form by individuals chosen for their diverse perspectives and technical expertise, in accordance with procedures approved by the National Research Council’s Report Review Committee. The purpose of this independent review is to provide candid and critical comments that will assist the institution in making its published report as sound as possible and to ensure that the report meets institutional standards for objectivity, evidence, and responsiveness to the study charge. The review comments and draft manuscript remain confidential to protect the integrity of the deliberative process. We wish to thank the following individuals for their review of this report:
James Block, DTN-Meteorlogix, Minneapolis, Minnesota
David Budescu, University of Illinois, Champaign
Simon Chang, Naval Research Laboratory, Monterey, California
Holly Hartmann, University of Arizona, Tucson
Kathryn Laskey, George Mason University, Fairfax, Virginia
Daniel P. Loucks, Cornell University, Ithaca, New York
Tom Skilling, WGN-TV News, Chicago, Illinois
Mort Webster, University of North Carolina at Chapel Hill
Lawrence Wilson, Meteorological Service of Canada, Dorval, Quebec
Although the reviewers listed above have provided constructive comments and suggestions, they were not asked to endorse the report’s conclusions or recommendations, nor did they see the final draft of the report before its release. The review of this report was overseen by George Frederick, Vaisala, Inc., and Kuo-Nan Liou, University of California, Los Angeles. Appointed by the National Research Council, they were responsible for making certain that an independent examination of this report was carried out in accordance with institutional procedures and that all review comments were carefully considered. Responsibility for the final content of this report rests entirely with the authoring committee and the institution.