Meteorological and Hydrological Early Warning Systems

John W. Zillman
Bureau of Meteorology, 150 Street, Melbourne, Australia.
Tel. : +61-3-9669-400, Fax: +61-3-9669-4548,
E-mail: karen.green@bom.gov.au

The provision and operation of warning systems to prevent, or reduce, the loss of life and property from natural disasters of meteorological and hydrological origin has long been acknowledged as one of the most fundamental responsibilities of government and is one of the highest priority functions of National Meteorological and Hydrological Services around the world. Because the provision of forecasting and warning services for meteorological and hydrological phenomena is so heavily dependent on rapid access to information from beyond the national borders of threatened countries, their design and operation is based on the long standing policy and practice of co-operation and free and unrestricted data exchange under the Convention of the World Meteorological Organization (WMO). Although the warning systems in many countries are still at a fairly basic level of operation, it is clear from studies undertaken over recent years, especially within the framework of the IDNDR (International Decade for Natural Disaster Reduction), that an effective national warning system, operating within the framework of the WMO World Weather Watch, will repay its costs of installation and operation many times, in economic terms alone. Even more importantly, through the contribution of modern meteorological and hydrological science and technology such as meteorological satellites, weather radar, numerical prediction models and so on, it is possible to provide communities in the path of major potential disasters from tropical cyclone, flood, fire, severe storm, and even drought, with the basis for early preparedness action which can avert enormous loss of life and social turmoil. Unfortunately, however, not all countries are yet in a position to reap the benefits of effective warning systems. Indeed there are some developments on the international scene which severely threaten the effectiveness, and even the continued operation, of the many excellent warning systems that do exist. The most serious threat is probably that flowing from the spread of national economic policies which undermine the highly co-operative regime of free and unrestricted exchange of data and technology which has underpinned the operation of WMO and National Meteorological and Hydrological Services around the world for more than a century. This paper argues for a strong reaffirmation of the fundamental importance of the global co-operation in data exchange and meteorological and hydrological service provision from which all countries benefit out of all proportion to the costs they bear. It suggests a number of policies and measures which will help avert the current threats and assist in enhancing the effectiveness of meteorological and hydrological warning systems and services over the coming decades.