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1 ~ Introduction FLOODS: A SIGNIFICANT NATIONAL HAZARD Floods are the most devastating of all weather-related hazards in the United States (see Figure 1-1~. Floods often produce tragic and disastrous extremes in losses of both life and property. Over the past 30 years floods have claimed an average of 139 lives per year compared with 87 lives lost per year by lightning, 82 by tornadoes, and 27 by hurricanes (NOAA, 1994a). (In recent years, the average annual flood-related death toll has risen to nearly 200.) During the same 30-year period, property damage caused by floods av- eraged approximately $1 billion per year. This amount is nearly twice that associated with tornadoes and hurricanes, and recently it has averaged nearly $2 billion per year. The continuing industrialization and population growth of river valleys are increasing the economic cost and death toll of flood-related disasters. Flash floods are an especially dan- gerous threat. A single flash flood in 1976 on the Big Thompson River in Colorado claimed 139 lives. After the Great Midwest Flood of 1993, property damage was esti- mated at $15 billion. Since the 1993 Midwest Flood, seven other weather-related disasters in the United States have each caused over $1 billion in damages; five of these seven disas- ters were floods. Overall, 75 percent of all presidential disas- ter declarations are for flood damage, and more than 85 per- cent of disaster declarations result from weather of all types (Chapman, 1992; NOAA, 1995a). At the opposite extreme from floods, prolonged droughts also bring major economic and social disruption by losses in agriculture and food production. Furthermore, low-flow con- ditions in streams and rivers associated with droughts have adverse ecological effects on fish populations and riparian zone (river-bank) habitats. Low-flow conditions also impact navigation and industrial activities that are dependent on water in the river network. For example, river commerce in the upper Midwest literally bottomed out after the devastat- ing drought of 1988, which had an economic toll exceeding $40 billion. Drought conditions in 1996 have caused crop losses estimated in the hundreds of millions of dollars in central and southwestern regions of the United States. Many of the nation's watersheds are now managed and controlled through flood control reservoirs, storage reser- voirs, hydroelectric production, water quality and erosion control measures, and land management. The operation and optimum management of these systems require forecasts on time scales that range from hours to seasons. The economic benefit of providing accurate hydrologic projections for these activities is estimated by the National Weather Service (NWS) to approach $1 billion or more annually (NWS, 1996a). The NWS is charged by Congress to provide flood fore- casts and warnings to the public to protect life and property. The NWS mission in hydrology services also extends to the provision of basic hydrologic forecast information to pro- mote the nation's economic and environmental well-being (Starlings and Wenzel, 1995~. Many types of hydrology products and services support a wide range of user commu- nities. User communities include the general public, the news media, emergency managers at all levels of government, public works and safety agencies, and water resource and floodplain managers throughout the United States. MODERNIZATION OF TH E NATIONAL WEATHER SERVICE The NWS is currently undergoing a comprehensive mod- ernization and associated restructuring program that is in- tended to improve substantially weather and hydrologic warning and forecast products and services) in the United States. The modernization of the NWS, under way for over a decade, entails the deployment of proven observational, information processing, and communications technologies and the establishment of an associated operational structure. The goal of the modernization program is to ensure that the tin the context of this report, any technical output from the NWS, whether from one office to another or to external users, is a "product." The term "guidance," also used often in this report, describes products used internally or between offices. 6

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INTRODUCTION 7 am. me. be. . A' . ma. ~: . ~ . ~ . ~. - $ m~ . fat, I- ~N ~ ~I ~: At, ~ . F ~ - ~- . "q - 7~ iiF ~it- ~ ~ ~ Alaska :~: Be. .` ~ \. ~ hi . \ . ok. ~ Hawaii Puerto Rico FIGURE 1-1 Notable floods and flash floods from 1987 to 1991. Source: NWS (1992~. major scientific and technological advances that have been made in the ability to observe and understand the atmosphere are applied to the practical problems of providing weather and hydrologic services to the nation. The new observing systems include the Weather Surveil- lance Radar 1988 Doppler (WSR-88D) Next Generation Weather Radar (NEXRAD), the Automated Surface Observ- ing System (ASOS), and the Next Generation Geostationary Operational Environmental Satellites (GOES-Next). An Advanced Weather Interactive Processing System (AWIPS) will provide critical information processing, interactive fore- cast environments at each field office, and a vital, high-speed communications link among all the offices. The associated restructuring of the NWS is driven by these new technologies. The premodernization field office structure included 52 Weather Service Forecast Offices (WSFOs); approximately 200 smaller offices (mostly Weather Service Offices [WSOs], which take manual weather observations and issue local-area forecasts based on guidance from the WSFOs as well as warnings based on a local weather radar); and 13 River Forecast Centers (RFCs). The modernized structure of the NWS includes 13 RFCs and Deaths Damage >500,000 119 Weather Forecast Offices (WFOs)2 at locations deter- mined primarily by the coverage of NEXRAD systems in- stalled nearby.3 In January 1991 the NWS Office of Hydrology first pub- lished its Hydrometeorological Service Operations for the 1990s (NWS, 1991, 1996a). This plan, most recently up- datedin March 1996, describes the activities at RFCs, WFOs, and regional and national headquarters offices for the vari- ous transition phases that lead up to and extend into the era of the modernized and restructured NWS. The plan includes the status of critical path decisions and policies, staffing 2The original strategic plan (DOC, 1989) for restructuring of the NWS called for 115 WFOs. Staffing analyses by the NWS led to the decision to assign a total of 78 service hydrologists to the WFOs. In the intervening years since the strategic plan was published, various activities, the most recent being a study of NEXRAD coverage (NRC, 1995), have led to ad- justed totals of 119 WFOs and 80 service hydrologists. Although final bud- get approval for this planning baseline is not complete, the remainder of this report cites 119 WFOs and 80 service hydrologists. 3 The spatial responsibilities of RFCs are determined by physiographic boundaries (watershed basins) whereas WFO boundaries are geopolitical (counties).

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8 ASSESSMENT OF HYDROLOGIC AND HYDROMETEOROLOGICAL OPERATIONS AND SERVICES analysis, a master training plan, and a hydrologic systems support plan. The l990s plan has received wide distribution within the NWS and reflects the policy, technical, and pro- grammatic decisions coordinated by NWS headquarters, re- gional offices, and field office managers. SCOPE AND ORGANIZATION OF THE REPORT With the implementation of a new network of advanced weather radars nationwide as part of the modernization pro- gram, and with the concomitant availability of advanced communication and computation technologies, the NWS will have an unprecedented opportunity to deliver highly im- proved hydrology forecast and warning products and ser- vices to the public. This report addresses technical and man- agement issues that affect the realization of that opportunity. The modernization of hydrologic services in the NWS is considered in its entirety tools and techniques, observation systems, operations, and management are all discussed. Each component contributes to the issuance of hydrologic forecasts and warnings at some stage in the life cycle of forecast prepa- ration. Therefore all of these topics must be critically evalu- ated as part of an overall assessment of the modernized NWS and its readiness to deliver advanced and improved hydro- logic forecast products and services to the public and other user communities. In Chapter 2 the interactions between hydrology and me- teorology in the NWS, both before and after the current mod- ernization, are described. A particular focus is placed on the roles and responsibilities of the RFCs and WFOs in the mod- ernized NWS. Chapter 3 presents a discussion and evalua- tion of the various tools and techniques, observation inputs, operations, and products and services that comprise the mod- ernization of hydrologic services. In Chapter 4 management and operational support issues such as leadership, research and development, operational test and evaluation, staffing, and training are discussed. All of the committee's recom- mendations appear in Chapters 3 and 4. Finally, Chapter 5 presents a brief synoptic assessment of the direction and out- look for the modernization of hydrologic products and ser- vices in the NWS.