Committee to Assess the National Weather Service Advanced Hydrologic Prediction Service Initiative Water Science and Technology Board Division on Earth and Life Studies THE NATIONAL ACADEMIES PRESS Washington, D.C. www.nap.edu THE NATIONAL ACADEMIES PRESS 500 Fifth Street, N.W. Washington, DC 20001 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 panel responsible for the report were chosen for their special competences and with regard for appropriate balance. Support for this study was provided by the National Weather Service under Contract No. 50-DGNA-1- 90024, T.O. 26. Any opinions, findings, 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. International Standard Book Number 0-309-10144-1. th Additional copies of this report are available from the National Academies Press, 500 5 Street, N.W., Lockbox 285, Washington, DC 20055; (800) 624-6242 or (202) 334-3313 (in the Washington metropolitan area); Internet, http://www.nap.edu. Copyright 2006 by the National Academy of Sciences. All rights reserved. Printed in the United States of America. The National Academy of Sciences is a private, nonprofit, self-perpetuating society of distinguished scholars engaged in scientific and engineering research, dedicated to the furtherance of science and technology and to their use for the general welfare. Upon the authority of the charter granted to it by the Congress in 1863, the Academy has a mandate that requires it to advise the federal government on scientific and technical matters. Dr. Ralph J. Cicerone is president of the National Academy of Sciences. The National Academy of Engineering was established in 1964, under the charter of the National Academy of Sciences, as a parallel organization of outstanding engineers. It is autonomous in its administration and in the selection of its members, sharing with the National Academy of Sciences the responsibility for advising the federal government. The National Academy of Engineering also sponsors engineering programs aimed at meeting national needs, encourages education and research, and recognizes the superior achievements of engineers. Dr. Wm. A. Wulf is president of the National Academy of Engineering. The Institute of Medicine was established in 1970 by the National Academy of Sciences to secure the services of eminent members of appropriate professions in the examination of policy matters pertaining to the health of the public. The Institute acts under the responsibility given to the National Academy of Sciences by its congressional charter to be an adviser to the federal government and, upon its own initiative, to identify issues of medical care, research, and education. Dr. Harvey V. Fineberg is president of the Institute of Medicine. The National Research Council was organized by the National Academy of Sciences in 1916 to associate the broad community of science and technology with the Academy’s purposes of furthering knowledge and advising the federal government. Functioning in accordance with general policies determined by the Academy, the Council has become the principal operating agency of both the National Academy of Sciences and the National Academy of Engineering in providing services to the government, the public, and the scientific and engineering communities. The Council is administered jointly by both Academies and the Institute of Medicine. Dr. Ralph J. Cicerone and Dr. Wm. A. Wulf are chair and vice chair, respectively, of the National Research Council. www.national-academies.org COMMITTEE TO ASSESS THE NATIONAL WEATHER SERVICE ADVANCED ∗ HYDROLOGIC PREDICTION SERVICE INITIATIVE SOROOSH SOROOSHIAN, Chair, University of California, Irvine RICHARD A. ANTHES, University Corporation for Atmospheric Research, Boulder, Colorado DARA ENTEKHABI, Massachusetts Institute of Technology, Cambridge EFI FOUFOULA-GEORGIOU, University of Minnesota, Minneapolis WILLIAM H. HOOKE, American Meteorological Society, Washington, DC GEORGE H. LEAVESLEY, United States Geological Survey, Denver, Colorado GLENN E. MOGLEN, University of Maryland, College Park BURRELL E. MONTZ, Binghamton University, Binghamton, New York DOUG PLASENCIA, Michael Baker Jr., Inc., Phoenix, Arizona LIMING XU, FM Global Research, Norwood, Massachusetts NRC Staff LAUREN E. ALEXANDER, Study Director DOROTHY K. WEIR, Research Associate ∗ The activities of this committee were overseen and supported by the National Research Council’s Water Science and Technology Board (see Appendix B for listing). Biographical information on committee members and staff is contained in Appendix C. v Preface Floods and droughts cause loss of life and enormous damage to the nation’s economy. Thus, hydrologic forecasting, the primary means of obtaining warnings regarding the timing and extent of these events, is critical to public safety and the economy. The National Weather Service (NWS) operates 13 river forecast centers in the United States to produce both short- and long-term river flow/stage forecasts at about 4,000 locations. In the interceding years since the river forecast offices were formed in the 1960s, tremendous change and growth have occurred in fields related to and affected by hydrologic forecasting. Urban, industrial, and population growth have increased occupation of flood-prone regions. The frequency of heavy rainfall events is increasing world-wide. Advanced technologies, applied research, and exponential advancements in web-based applications present both challenges and opportunities. In light of these changes, the NWS reassessed its hydrologic services and determined that enhancements are necessary to sustain its mission: to provide water information for decisions to protect life and property, and thereby contribute to the health of the nation's economy. The Advanced Hydrologic Prediction Service (AHPS) initiative grew out of this assessment. This report is a product of the Committee to Assess the National Weather Service Advanced Hydrologic Prediction Service Initiative. This committee was formed in response to a request from the Office of Hydrologic Development of the National Oceanic and Atmospheric Administration’s (NOAA) NWS and was charged to review and assess the full scope of AHPS, an NWS program, aimed at improving the nation’s river forecasts. The committee was organized under the auspices of the Water Science and Technology Board of the National Research Council (NRC). AHPS, as planned, will include a suite of web-based products designed to improve river, flood, and water resource forecasting abilities nationwide. Specifically, through AHPS, the NWS aims to provide better forecast accuracy, more specific and timely information on fast-rising floods, new types of forecast information, longer forecast horizons, easier-to-use products, and increased, more timely, and consistent access to information. AHPS products and information are planned to cover future hydrologic events on time scales from minutes to months. These new services should support more informed decisions through timely and accurate hydrologic forecasts. The charge to our committee was to provide an assessment of the AHPS program. The committee met four times between February and November 2004 in open and closed sessions. NOAA/NWS employees, representatives from other related federal agencies, and water resource and emergency management practitioners attended and participated in open sessions. Recognizing the multiple layers involved in developing a national hydrologic services program, the committee evaluated the scientific and technical as well as the programmatic aspects of the AHPS initiative. Mid-course in the study, the committee split into small groups and visited sites across the country to collect information and better understand how federal, state, and regional agencies use hydrologic forecast data. During these site visits, committee members conducted identical surveys (see Appendix A) to assess interpretations of the AHPS effort. Committee members visited the Northwest River Forecast Center, the Portland National Water and Climate Center, and the Bonneville Power Administration in Portland, Oregon; they also visited the National Operational Hydrologic Remote Sensing Center, the NWS Forecast Office—Twin Cities, the North Central River Forecast Center in Chanhassen, Minnesota, and the Susquehanna River Basin Commission. vii vi Preface Examples and lessons learned from the field studies are interspersed throughout the report, and a synopsis is presented in Appendix A. AHPS is on an incremental implementation timeline that started in 1997 and will be complete in 2013. This assessment of AHPS comes at a productive time, in that the program still has several years before it is fully implemented. The committee views AHPS as an important, worthy program and drafted this report to provide constructive comments to help the NWS realize its laudatory goals. Major findings and recommendations are presented in bold text. We have many people to thank for their help over the course of this project and in the preparation of this report. The NWS Office of Hydrologic Development personnel were incredibly supportive of our committee and its progress towards report completion. We express appreciation to George Smith, Gary Carter, General D. L. Johnson, David Kitzmiller, Michael Smith, Eric Strem, and Janice Sylvestre of the NWS. We also thank Newsha Ajami, Kristie Franz, Bisher Imam, and Hamid Moradkhani of the University of California, Irvine; Gary Bardini, California Department of Water Resources; Larry Brazil, Riverside Technology, Inc.; Erik Hagen, Interstate Commission on the Potomac River Basin; Robert Hirsch, U.S. Geological Survey; Phil Pasteris, Natural Resources Conservation Service; Adam Walden, County of Los Angeles Department of Public Works; and David Wingerd, U.S. Army Corps of Engineers for their participation and insight. The report and study process would not have been possible without the hard work of NRC staff members Lauren Alexander and Dorothy Weir. Finally, I would like to recognize my fellow committee members for their long hours and dedication to reviewing the AHPS project and advancing the science and application of hydrologic prediction. 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 NRC’s Report Review Committee. The purpose of this independent review is to provide candid and critical comments that will assist the NRC in making its published report as sound as possible and will 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: Frederick H. Carr, University of Oklahoma; Susan L. Cutter, University of South Carolina; Witold Krajewski, University of Iowa; Dennis P. Lettenmaier, University of Washington; Fred L. Ogden, University of Connecticut; Robert T. Ryan, National Broadcasting Company; Robert J. Serafin, National Center for Atmospheric Research; and C. Larry Winter, National Center for Atmospheric Research. Although the reviewers listed above have provided many constructive comments and suggestions, they were not asked to endorse the conclusions or recommendations, nor did they see the final draft of the report before its release. The review of this report was overseen by Debra S. Knopman of the Rand Corporation. Appointed by the NRC, she was 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. Soroosh Sorooshian, Chair Contents SUMMARY 1 1 INTRODUCTION 8 Flood Losses in the United States, 8 Hydrologic Services, 9 Advanced Hydrologic Prediction Service, 10 The National Research Council Study, 12 References, 15 2 PROGRAMMATIC FOUNDATIONS OF AHPS 17 Purpose and Benefits of AHPS, 17 Organizational Context for AHPS, 18 Evaluation of AHPS Programmatic Elements, 19 Chapter Summary, 29 References, 30 3 SCIENTIFIC AND TECHNICAL ASPECTS OF AHPS 31 Precipitation Inputs to Hydrologic Models, 31 The NWS River Forecast System, 33 Flash-Flood Guidance, 44 Chapter Summary, 45 References, 48 4 AHPS USERS 50 Range and Needs of AHPS Users, 50 Reaching AHPS Users, 53 Feedback from AHSP Users, 58 Chapter Summary, 63 References, 64 ACRONYMS 65 APPENDIXES A Site Visits 69 B Water Science and Technology Board 71 C Committee and Staff Biographical Information 72 ix