Toward a New Advanced Hydrologic Prediction Service (AHPS)

85 Pages·2016·2.89 MB·English

by  National Research Council, Committee to Assess the National Weather Service Advanced Hydrologic Prediction Service Initiative

Committee to Assess the National Weather Service
Advanced Hydrologic Prediction Service Initiative

Water Science and Technology Board

Division on Earth and Life Studies

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provided support for the project.

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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.
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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.
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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
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