|Volume 57(1) — January 2008
The World Weather Watch today
In January 2003, James Rasmussen provided a brief history of WMO’s World Weather Watch for the WMO Bulletin. He recalled that, in April 1963, “Fourth World Meteorological Congress approved the concept of the World Weather Watch (WWW) and set the World Meteorological Organization on the journey that dramatically changed and enhanced the development of meteorology and the atmospheric sciences”. The advent of the space age was the spark that ignited this seminal event. Following the launches of Sputnik by the USSR in 1957 and TIROS by the USA in 1960, US President John F. Kennedy addressed the United Nations General Assembly, seeking ways to exploit the peaceful uses of outer space. The rest is history—as recorded in Rasmussen’s article.
Since 2002, there have been a number of initiatives and accomplishments having a significant impact on the World Weather Watch. Indeed, not since the 1960s has there been so much emphasis and worldwide attention on the knowledge of the environment—highlighted in December 2007, by the award of the Nobel Peace Prize to the Intergovernmental Panel on Climate Change and Albert Gore Jr “for their efforts to build up and disseminate greater knowledge about man-made climate change, and to lay the foundations for the measures that are needed to counteract such change”. With regard to the World Weather Watch, there have been three important decisions that are moulding a future World Weather Watch designed to ensure improved meteorological, hydrological and environmental services by pushing the bounds of science and technology to meet societal needs—and continuing to demonstrate WMO’s international leadership in weather, climate and water products and services.
First, Fourteenth World Meteorological Congress (May 2003) decided to embark on a major enhancement of the World Weather Watch’s Global Telecommunication System with an initiative called the WMO Information System (WIS). Second, in July 2003 and at the invitation of the USA, 33 nations and the European Commission joined together at the first Earth Observation Summit (EOS-I) to adopt a declaration that called for action in strengthening global cooperation on Earth observations. Third, Fifteenth World Meteorological Congress (May 2007) decided to move towards enhanced integration of WMO observing systems.
The three above events are the cornerstones of a paradigm shift for WMO Members. In order to appreciate better the changes, this article reviews the World Weather Watch as it existed in 2002 and summarizes subsequent initiatives.
The World Weather Watch in 2002 and now
The primary purpose of the WWW in 2002 was to ensure that all WMO Members obtained the meteorological information they required, both for operational work and for research, and this purpose remains the driving force. The WWW is a global system composed of national facilities and services provided by individual Members, coordinated, and in some cases supported, by WMO and other international organizations.
The essential elements of the WWW in 2002 were the:
In today’s paradigm, the GOS is evolving into the WMO Integrated Global Observing Systems (WIGOS) and the GTS is being built upon and expanded into the WMO Information System (WIS). Indeed, WIGOS is the bond that brings together all WMO and sponsored observing systems into a system of observing systems. The re-named Global Data-processing and Forecasting System (GDPFS) increases the emphasis on the numerical weather prediction (NWP) aspect of data processing as part of the weather-forecasting process, for all ranges in time.
Global Observing System (GOS)
The Global Observing System is comprised of a space-based system of environmental satellites and a surface-base network of diverse upper-air and surface observing systems.
Space-based system of environmental satellites
Two major advances have characterized the evolution of meteorological observations at the Earth’s surface. The first is the development of automated weather-observing technologies that have permitted the more efficient use of personnel and allowed for the deployment of observing systems in more remote locations. The second advance has been the major improvement in observations over the ocean.
WMO Integrated Global Observing Systems (WIGOS)
There is a broadly recognized need for a comprehensive, coordinated and sustainable global observing system which integrates diverse space- and surface-based observing systems holistically in a fashion which optimizes knowledge of current environmental conditions and the exploitation of this information for predictive weather, climate and water products and services. Many international agencies have to administer systematically these diverse arrays of systems and have developed data policies and programmes to meet their needs. Fifteenth Congress adopted the WMO Integrated Global Observing System (WIGOS) concept, which is the organizational response of WMO to this need for integration. Strong cooperation is therefore needed among all partners to accomplish the broad integration objectives.
WIGOS is a comprehensive, coordinated and sustainable system of observing systems, which is based on the observational requirements of all WMO programmes. It ensures the availability of required data and information and facilitates access through the WMO Information System according to identified temporal, geographical and organizational requirements, including those for real-, near-real-time and delayed modes. In so doing, it respects data-sharing policies and helps ensure high data-quality standards and benefits.
The surface- and space-based components of WIGOS include weather observing networks (e.g. WWW/GOS, Aircraft Meteorological Data Relay, Automated Shipboard Aerological Programme); atmospheric composition observing networks (e.g. Global Atmosphere Watch); radiation observing networks (e.g. Baseline Surface Radiation Network); marine meteorological networks and arrays (e.g. Voluntary Observing Ships, drifting and moored buoy arrays); hydrological observing networks (e.g. components of the World Hydrological Cycle Observing System); and the various atmospheric, hydrological, oceanographic and terrestrial observing systems contributing to the Global Climate Observing System. Improved monitoring through the integration of surface- and space-based observations is essential for understanding global climate and the components of the global climate system: atmosphere, hydrology, ocean, land surface and cryosphere.
WIGOS development and implementation will proceed in parallel with the planning and implementation of the WMO Information System. The combination of both efforts will allow for an integrated WMO end-to-end system of systems designed to improve Members’ capability to effectively provide a wide range of services and to better serve research programme requirements.
WIGOS will create an organizational, programmatic, procedural and governance structure that will significantly improve the availability of observational data and products. It will provide a single focus for managing all WMO observing systems, as well as a mechanism for interactions with co-sponsored observing systems. Integration will lead to efficiencies and cost savings that can be reinvested to overcome known deficiencies and gaps in the present structure and working arrangements.
WIGOS aims to:
The concept of WIGOS is based on the premise that agreed-upon general standards and recommended practices will apply to all WMO and sponsored observing systems and Programmes.
As a system of observing systems, integration will be accomplished at three levels:
Benefits of WIGOS to Members and partner organizations of WIGOS include:
Global Telecommunication System (GTS)
The communication needs of National Meteorological Services for data collection and information exchange have been met largely through the implementation and development of the Global Telecommunication System. Based on the technology available in the 1970s (leased telegraphic and telephone lines), the system topology was built around connectivity to countries and consisted of three World Meteorological Centres (WMCs) (Moscow, Washington and Melbourne) and a series of Regional Telecommunication Hubs (RTHs), which connected Members’ National Meteorological Centres (NMCs) to the Main Telecommunications Network.
A data-management framework was developed for this network that included catalogues of metadata for content of messages and observation stations’ reports, as well as distribution catalogues detailing where information originated and which Member States subscribed to what information. These catalogues allowed messages containing only dynamic data to be sent, thereby increasing the efficiency and speed of the system.
The GTS continues to function on three levels:
Over the years, the plan for the GTS has progressed from the original “store-and-forward” system with its mix of automatic and manned facilities requiring extensive management, which was prone to outages and failures (especially at the regional level), to a combination of data-distribution systems via telecommunication satellites with national, regional and multi-regional coverage, complementing meshed data-communication networks and traditional point-to-point circuits. GTS implementation has to match the whole range of WMO Members’ requirements and capabilities, from Least Developed Countries to the most advanced States. The great strength of the WWW GTS is that it allows telecommunication connections between Members and within and between Regions to be determined by the Members concerned as long as international exchange commitments and protocols, as internationally agreed upon and set down in the WMO Technical Regulations, are met.
The GTS has been continually under review within WMO’s Commission for Basic Systems (CBS) and the six WMO regional associations and planning for upgrading the global and regional components of the system to take advantage of the revolutionary changes in information and communications technology (ICT)—whilst ensuring that every Member receives the meteorological information it requires—is a high priority.
Extensive international collaboration allowed the development of message standards and codes which further improved GTS functionality and efficiency. In particular, special coding known as traditional alphanumeric codes (TAC) were developed to allow observations and messages to be passed around the network efficiently. Originally telegraphically based, the GTS quickly evolved, using a series of data links over private telephone-type international links to connect the RTHs. The GTS was further enhanced by the inclusion of facsimile graphics technology for the sharing of scanned and image- based products. Migration to the ITU-X25 communications protocol in the 1980s then allowed the GTS to handle binary data, as well as TAC and facsimile, while ensuring error-free transmissions. The exchange of binary information, as well as text, enabled codes to be developed, utilizing binary compression based on tables, which allowed even more information to be exchanged for a given capacity.
The communication pipes connecting the RTHs and NMCs also evolved with rapidly advancing technology, including, in more recent years, frame relay, asynchronous transfer mode, multi-protocol label switching and other advanced managed data-communication networks. Aside from being considerably more cost-effective to run in most countries, these networks facilitated rapid improvements and upgrades of the GTS. The fast development of the Internet and related ICT was a huge opportunity, enabling even more sophisticated and commercial off-the-shelf message-handling capabilities at lesser costs that fostered a strong and fast migration to Internet-type protocols on the GTS.
The rapid migration of the GTS to international industry standards and technology, together with off-the-shelf hardware and software systems, has been a great capacity-building opportunity for developing countries, enabling rapid implementation of advanced information and communication systems for many. This, in turn, allowed the use of different versatile networking technologies, including, when necessary, the Internet being used to supplement the GTS private links. In some cases, especially developing countries and Least Developed Countries, the Internet is the only affordable telecommunication means, despite its inherent operational security risks and limited resilience in case of major events with public impact, including natural disasters. The GTS is fundamentally a private communication system connecting WMO’s National Meteorological and Hydrological Services on a wide area network, as depicted in Figure 3, ensuring the exchange of time- and operation-critical data and products. The status of GTS implementation in Asia in August 2007 can be found at http://www.wmo.int/pages/prog/www/TEM/GTSstatus/R2rmtni.gif.
The asset of a closed wide-area network such as the GTS is that it remains under full control of NMHSs, with a guaranteed quality of service ensuring high-priority traffic. The drawback is that, despite its rapid improvements, its capacity to handle data volumes is limited by the cost of connectivity between centres. In contrast, the Internet can generally handle large volumes and, since the early 1990s, driven by the growing data volumes associated with improving numerical weather prediction models and rapidly increasing data volumes associated with remote-sensing from new improved satellite systems, some NMHSs established bilateral links for exchanging data and, in more recent years, via the Internet.
WMO programmes other than the World Weather Watch were also developing information exchange with diverse data-management approaches outside the GTS data- management framework and NMHS information-management systems had to cope with multiple sources of data, while the GTS catalogues no longer represented all the information that was available to WMO Members. Eventually, it was recognized that these diverse information and communication developments were generating inefficiencies and/or duplication, as well as a deteriorating overall cost-effectiveness.
WMO Information System
It was in this environment that the WMO Information System initiative was developed (CBS, 1992). WIS incorporates the connectivity of the GTS, the flexibility of new systems, such as the Internet, while ensuring that the data-management framework is capable of encompassing all WMO information. This new model simply moves the focus from connectivity through the GTS and Internet to data, products and their management (i.e. the perspective shifts from communications-centric to data-centric).
Fourteenth World Meteorological Congress formally adopted the concept of WIS, stating that an overarching approach for solving the data-management problems for all WMO and related international programmes was required.
As the single, coordinated global infrastructure, WIS will:
The fundamental design of WIS was originally developed by an Inter-Commission Task Team and several key pilot projects were initiated to test and develop some of the principles. Following recognition of the need to implement WIS and in view of the overarching nature of WIS across all programmes, Congress set up an Inter-Commission Coordination Group on WIS which met for the first time in January 2005. Technical commissions were instructed to provide resources and support for WIS development.
Fifteenth Congress agreed that WIS would provide three fundamental types of services to meet different requirements:
Fifteenth Congress reinforced the need for WIS and for accelerated implementation and emphasized a requirement for WIS to work closely with, and facilitate the communications and information-management needs of, a WMO Integrated Global Observing System. Congress supported the time frame for the development and implementation of WIS implementation, aiming at the first operational global WIS centre by the end of 2008.
Global Data Processing and Forecasting System (GDPFS)
The original WWW Plan focused on the establishment of three World Meteorological Centres and anticipated that a number of Regional Meteorological Centres would eventually emerge. The operational concept was that the WMCs would undertake the task of assembling data (information such as output fields from global numerical weather prediction models) and their interpretation for use by the various RMCs. These, in turn, would add a level of more detail in order to support the National Meteorological Centres in their service-provision responsibilities. The structure of the GDPFS has evolved and some 25 Regional Specialized Meteorological Centres (RSMCs) have geographical specialization. These centres run a suite of models and analyses particularly designed and tuned to provide forecasting guidance for a particular topographical or ocean area, often using data sources and knowledge of a local or regional nature, e.g. surface networks and weather radars.
In addition, six RSMCs have tropical cyclone forecasting responsibility and eight have responsibilities for atmospheric transport modelling for environmental emergency response (nuclear accident, volcanic eruption, smoke from large fires or other emergencies). These centres have recently implemented a new operational capability to conduct “back-tracking” simulations for estimating the source of airborne material that has been detected, such as for the Comprehensive Nuclear-Test Ban Treaty’s verification system. In addition, several designated RSMCs provide medium-range weather forecasts, drought monitoring and prediction and extended- and long-range forecasts, as well as ultraviolet-index forecasts.
Approximately 80 National Meteorological Centres have implemented some level of numerical prediction capability, ranging from full global models to limited-area models to higher-resolution mesoscale models, some in collaborative consortia of several NMCs. While not running their own models, many other NMCs benefit from numerical prediction outputs.
A high-priority GDPFS focus area since 2002 has been to improve the delivery and exploitation of numerical weather prediction data for severe weather forecasting in developing countries. The Severe Weather Forecasting Demonstration Project (SWFDP) was initiated in 2006 with its first project in south-eastern Africa as a year-long pilot to demonstrate the value of delivering and exploiting existing NWP products in five countries (Botswana, Madagascar, Mozambique, United Republic of Tanzania and Zimbabwe). It included training for forecasters in how to use the products to improve severe weather forecasts and warnings for heavy precipitation and strong winds.
Anchored at the RSMC in Pretoria, South Africa, and supported by NWP centres in the USA, the United Kingdom and the European Centre for Medium-Range Weather Forecasts, this pilot project demonstrated great success by delivering a number of tailored NWP-based weather- forecasting products around the clock, including a daily synthesized forecasting guidance product (RSMC Pretoria) to assist forecasters at the NMHSs in the five participating countries.
All countries reported significant improvements to their weather forecasting and warning programmes. The NMHSs are also benefiting from many applications of NWP for a wide range of meteorological services. In 2007, it was decided to continue these products operationally and indefinitely and to broaden their availability to all 14 Members of the South African Development Community. In addition, in coordination with WMO’s Public Weather Services and Disaster Risk Reduction Programmes, the initiative is being further developed to improve operational services and exchange and linkages between participating NMHSs and their home country public weather services users, including emergency management authorities. Looking to the future, the SWFDP will be considered for additional implementation throughout WMO Region I and in other WMO Regions.
There are a number of other GDPFS initiatives, including the infusion of probabilistic and ensemble-based science into operational use, improved fine-scale modelling at RSMCs and national centres, expanded use of ever-improving NWP products in many meteorological applications and improved international collaboration on long-range forecasting, to improve NMHS products and services and provision of training. The GDPFS has seen a steady collective evolution through continuous improvements in scientific and technological developments, the establishment of standards for product exchange and the provision of training and capacity-building measures for NMHSs of developing countries.
In recent years, numerical weather-prediction technologies have attained significant skill and usefulness for many meteorological applications over a wide range of space- and time-scales, increased lead-times for anticipating significant meteorological events and factors, as well as for new approaches to solving weather and environmental prediction problems. Nonetheless, reviewing the concepts behind WIGOS and WIS, it would seem that the GDPFS is the remaining infrastructure component of the World Weather Watch that has not yet experienced planned re-engineering and new integration of all aspects of operational meteorological data processing for weather and environmental predictions and applications. WMO’s -Strategic Plan for 2008-2011 places great emphasis on service delivery and formally recognizes both WIGOS and WIS. It is conceivable that next World Meteorological Congress could agree to establishing a WMO Forecast System to further underpin service delivery within a trilogy. What might it look like?
A WMO Forecast System?
WMO established the WWW GDPFS as a global network of World Meteorological Centres, Regional Specialized Meteorological Centres and National Meteorological Centres to meet the weather-, climate- and water-forecasting needs of its Members. This system successfully processes observations through data assimilation and produces forecast information on global, regional and local scales in the form of generalized and specialized products needed by NMHSs to develop routine weather, climate and water products and forecasts and warnings for the protection of life and property during high-impact weather, climate and water events. Although the original WWW GDPFS paradigm has served the hydrometeorological user community well over the past decades, new scientific and technological trends offer significant opportunities for accelerated improvements and broadened benefits in the coming years.
One emerging theme is the recognition of the need for probabilistic information regarding the future state of weather, climate and water systems. Each forecast inherently contains uncertainty and, for optimal decision-making, users must consider this uncertainty. Scientific developments point in the direction of ensemble forecasting as the best practical approach to probabilistic forecasting. Ensemble forecasting can capture not only the most likely forecast scenario in weather, climate and water conditions but also the uncertainty associated with any forecast. While most NWP centres that run global models are also running ensemble systems, a number of these, as well as other NMCs, are collaborating and have implemented ensembles based on an “ensembling” of outputs from several independently run NWP systems for predictions from the short to the long range.
A second and related theme is the recognition of the need for user-oriented products and services. This goes beyond standard basic forecast information and may include tailored products and services that are driven by the needs of, and are directly relevant to, health, energy, ecology and other applications. Considering the first theme, such products and services must also take the form of probabilistic guidance for maximum impact.
A third theme is the emergence of new technological features, such as the modern worldwide telecommunication system, including the Internet and the World Wide Web, allowing instant and distributed access to products and services; the open software development environment, greatly expanding the scope for international collaboration within and between the operational and research communities; and the ever-increasing power of computers, greatly expanding NWP and related processing capabilities. The WMO Information System and the WMO Integrated Global Observing System build on all these developments.
Researchers in the WMO Commission for Atmospheric Sciences/World Weather Research Programme/Observing System Research and Predictability Experiment (THORPEX) programme are actively engaged in expanding the scientific basis for the first two themes above. Regarding the first theme, an important component of forecast uncertainty is the use of imperfect numerical models over and above imperfect knowledge of the initial state of the atmosphere-land surface-ocean system. Research and developmental studies using data from the THORPEX Interactive Grand Global Ensemble (TIGGE) project and the North American Ensemble Forecast System for weather time-scales, as well as data from the European DEMETER project for the seasonal time-scale point to the value of combining ensemble forecasts generated by various numerical prediction centres across the globe.
Regarding the second theme, it is envisaged that user needs may influence not only the end product but also feedback all the way to the choice of observations taken, models and other processing tools used, depending on how specific high-impact weather, climate and water events may affect user groups, leading to a GDPFS that is adaptively configured, from the observing system to the user services and support level.
Building on the scientific and technological trends discussed above, a draft plan is being prepared by the THORPEX programme for the creation of a Global Interactive Forecast System (GIFS). Numerical ensemble forecasts relevant for particular applications will be collected from participating centres. The ensemble data will be statistically enhanced to eliminate systematic errors and render them more useful for practical applications (e.g. creation of probabilistic products and downscaling). The ensemble forecast data can then be subjected to additional, user-specific processing to support real-time access to specialized products and services for the WMO user community, especially in the least developed regions.
The GIFS takes advantage of current ensemble, NWP and other operational practices at existing WMCs and RSMCs, while the new functionalities can be carried out either at already existing and/or newly established WMCs and/or RSMCs. At the core of GIFS is multi-centre ensemble forecasting that offers a solution for generating an improved and seamless suite of products from the smallest and shortest time- and space-scales all the way to climate variability. At a later, more advanced stage, GIFS will also include capabilities to feed back user requirements adaptively to the Global Earth Observing System of Systems and the entire forecast process. As the scientific and technological advances merge, they will revolutionalize GDPFS, leading to a more powerful paradigm characterized by interactivity, adaptiveness and user responsiveness never seen hitherto.
As can be seen from this brief review, the World Weather Watch is alive and well. From the original concepts summarized in Rasmussen’s 2003 article to the present, important initiatives have been designed to improve the capabilities of NMHSs and there are exciting plans, programmes and possibilities for the future. I would be remiss not to highlight one of the most exciting strategic initiatives to emerge since the World Weather Watch—the Global Earth Observing System of Systems (GEOSS).
Mentioned briefly above, GEOSS is designed to integrate environmental information in a comprehensive and sustainable fashion and extend its utility to a number of additional socio-economic applications. The vulnerability of modern humanity, economies and the environment to high-impact weather, climate and water events was amply demonstrated by the 2004 Indian Ocean tsunami, droughts and disastrous flooding on every continent and severe weather including extreme heat and cold. Effective mitigation of the impacts of, and adaptation to, such events require accurate observation and prediction on global, regional and local scales, combined with enhanced capacity of disaster risk reduction managers and policy-makers to exploit this information. GEOSS provides a framework essential to support such action—and the WWW of the 21st century is a key contributor to this revolutionary new framework.
Rasmussen, J.R., 2003: Historical development of the World Weather Watch, WMO Bulletin 52 (1), 16-25.
World Meteorological Organization, 1992: Commission for Basic Systems, Abridged final report of the 10th session (WMO-No. 784), Geneva.