Contributing to Building a Weather-ready, Resilient and Sustainable Society

The vast majority of disasters are triggered by hydrometeorological hazards. Weather, climate and water impact society and all socioeconomic sectors. According to the Centre for Research on the Epidemiology of Disasters (CRED)–United Nations Office for Disaster Risk Reduction (UNISDR), 91% of the reported 7 255 disaster events recorded in the International Disaster Database 1998–2017 were related to hydrometeorological hazards. International policy frameworks, such as the Sendai Framework for Disaster Risk Reduction 2015–2030 (UNISDR 2015), recognize the multi-hazard nature of disaster risks as do decisions by the World Meteorological Congress and the WMO Executive Council

The National Meteorological and Hydrological Services (NMHSs) of WMO’s 192 Members provide reliable and timely weather, climate, hydrological and related environmental products and services to a wide range of users and partners. In most cases working around the clock, NMHSs play an essential role in reducing disaster risk and in mitigating and adapting to climate change. They do so primarily by producing and delivering weather forecasts and climate outlooks, warnings of hydrometeorological hazards, climate-variability predictions and climate-change projections. In addition, they coordinate outreach activities to enhance public awareness as well as the interpretation and use of their information products. They closely collaborate with disaster-risk and emergency management agencies to minimize loss of life and property, negative economic impacts, existing risks and the creation of new risks.

Service delivery is the continuous process for developing and delivering user-focused services, Products then depict basic information such as observations and datasets or information resulting from an analysis or forecast processes that the user will base a decision on (WMO 2014).

Weather, climate, and water-related service generation and delivery is thus a core business for each NMHS. For many years, the WMO community has focused on scientific and technical challenges, that is developing the basis for timely, reliable and accurate services. Meteorology, climatology, hydrology, oceanography and hydrogeology have developed their own approaches to service delivery. Various sectors that benefit from these services also use their own approaches to deal with the effects of hazardous events on the safety, efficiency and continuity of their operations, requiring distinct and customized hydrometeorological information.

NMHSs face challenges and opportunities due to globalization, urbanization, climate change and evolving information and communication technologies, as well as new and increasing user requirements. The need for timely information on what is occurring when, where and how in terms of relevant hydrometeorological phenomena, especially on clustered or cascading natural hazards and their impacts, calls for the delivery of integrated, seamless, impact-based and multi-hazard forecast and warning services.

Over the decades, WMO has addressed changing conditions and requirements through cross-cutting policies, strategies, plans, its regional associations, technical commissions, programmes, initiatives and capacity-development projects, covering all elements of the service generation and delivery process. WMO continues to leverage advancements in science and technology and to mainstream service dimensions and approaches to improve both the services and their delivery. NMHSs are shifting from a techno-centric modus operandi and data and product provision to a more integrated service-delivery approach, which benefits from the inclusion of social science and economics. These developments provide a good basis for further integration across disciplines, timescales and spatial levels, and among neighbouring countries and regions.


The Sendai Framework – A call upon the WMO community

The Sendai Framework for Disaster Risk Reduction 2015-2030 adopted in 2015 targets a “substantial reduction of disaster risk and losses in lives, livelihoods and health and in the economic, physical, social, cultural and environmental assets of persons, businesses, communities and countries”. During the negotiations, countries and partners highlighted the need to:

  • Invest in, develop, maintain and strengthen people-centred, end-to-end national early warning systems (EWS), as well as effective, nationally compatible, regional multi-hazard early warning mechanisms;
  • Promote the application of simple and low-cost early warning equipment and facilities broadening dissemination channels for early warning information to facilitate prompt action.
  • Broaden dissemination channels for early warning information to facilitate early action

To address these needs, States committed to attain global Target (g) of the Sendai Framework which aims to substantially increase the availability of and access to multi-hazard early warning systems (MHEWS) and disaster risk information.

The importance of EWS is also reflected in both the United Nations 2030 Agenda for Sustainable Development and the Paris Agreement Sustainable Development Goal (SDG) 3 “Ensure healthy lives and promote well-being for all at all ages” and SDG 13 “Take urgent action to combat climate change and its impacts” set targets for governments to strengthen EWS. The Paris Climate Agreement, Article 7 on enhancing adaptive capacity, strengthening resilience and reducing vulnerability to climate change” and Article 8 on loss and damage also place greater emphasis on strengthening EWS.


Building on achievements 

NMHSs generate economic and social value when their users benefit from decisions taken on the basis of the products and services they provide. Societal needs must be linked into the value chain for the production and delivery of services to aid in decision-making and action in order to have positive outcomes. It is also necessary to appreciate the role of communication, perception, interpretation and decision-making when developing services. The analysis and assessment of national socioeconomic benefits derived from the provision of regular services by NMHSs are a matter of utmost importance. 

NMHSs and their partners in academia, civil society and the private sector have made significant progress in improving quality and diversity in each component of the service value change. There have been advances in research, numerical modelling, observing capabilities (in situ and satellite) and computer and communication technologies. The WMO coordinated systems below offer a strong basis for them to build on in the future.


Meteorological, Climatological and Hydrological Services

Meteorological services provide information and advice on past, present and future states of the atmosphere; hydrological services on surface and subsurface inland waters; and oceanographic/marine services address the oceans. Traditionally, meteorological services have been divided into weather and climate services based on the characteristic timescales of weather – minutes to weeks – and climate –months to centuries. Climate information prepares users for the weather and its impact on the water cycle.

However, for most users climate and weather are mutually interchangeable, and in practice substantial overlaps exist between all these categories: weather services cover application areas such as aviation, transport and disaster-risk reduction; climate services often encompass early warning services for weather phenomena, as well as health and agricultural services; and hydrological services cover energy and water resource management. Such services may also be defined by the geographical area they target, such as urban areas, high mountains, polar regions or coastal zones.


The WMO Integrated Global Observing System / WMO Information System: The Global Observing System and the Global Telecommunication System (GTS) have enabled the monitoring and exchange of observational data in real time between Members and partners every day for more than 60 years. Without them, no WMO Member would be able to serve the needs of its citizens. 

Further progress depends on adopting a new, integrated approach in order to upgrade the global space- and surface-based observing systems in a fashion that optimizes knowledge of current environmental conditions and exploits the data they produce. The WMO Integrated Global Observing System (WIGOS) provides an over-arching framework for the coordination and optimized evolution of these systems (including GOS) that will continue to be owned and operated by an array of organizations and programmes. It will also support better use of existing and emerging observational capabilities, engaging regional and national actors for their successful integration. 

Similarly, the WMO Information System (WIS) is being built on the GTS to be capable of exchanging large data volumes, such as from new ground- and satellite-based systems and finer resolutions in models and their applications. WIS will be the vital data communications backbone, integrating real- and non-real-time, high-priority datasets, regardless of location. 


The Global Data-processing and Forecasting System (GDPFS)strengthens the capabilities of Members to meet the needs of users by sharing Numerical Weather Prediction (NWP) products and services at all time-scales, from minutes to decades. It encompasses all systems operated by Members (including those jointly coordinated with other international organizations, such as the International Civil Aviation Organization) and provides a framework for data exchange and delivery, the main support being WIS. 

Few Members have the operational capacity to implement such systems, owing to the high computational cost. Many of the latest NWP advances are particularly suitable for severe weather forecasting in tropical and subtropical regions but are supported only by leading NMHSs outside these regions. The Severe Weather Forecasting Demonstration Project (SWFDP) makes NWP products from the most advanced Members available to all others using a “cascading forecasting process”, whereby NMHSs receive guidance products from Regional Specialized Meteorological Centres (RSMCs), which, in turn, receive data and products from World Meteorological Centres. SWFDP has integrated impact-based service delivery for disaster risk reduction in its training curricula and is increasingly implemented and assessed jointly with other WMO demonstration projects for forecasting hazards such as flash floods and coastal inundation.


Hydrometeorological and derived hazards

According to the Terminology on Disaster Risk Reduction (UNISDR–UNGA, 2016), a hazard is “a process, phenomenon or human activity that may cause loss of life, injury or other health impacts, property damage, social and economic disruption or environmental degradation. (…) Hazards may be natural, anthropogenic or socionatural in origin. …hazards are socionatural in that they are associated with a combination of natural and anthropogenic factors, including environmental degradation and climate change. (…) Hazards may be single, sequential or combined in their origin and effects. Each hazard is characterized by its location, intensity or magnitude, frequency and probability. (…) Multi-hazard means (1) the selection of multiple major hazards that the country faces, and (2) the specific contexts where hazardous events may occur simultaneously, cascadingly or cumulatively over time, and taking into account the potential interrelated effects. (…) Hazards include biological, environmental, geological, hydrometeorological and technological processes and phenomena”.

Examples of hydrometeorological hazards are tropical cyclones, floods, droughts, heatwaves, cold spells and coastal storm surges. Hydrometeorological conditions may also be a factor in other, derived hazards induced by natural phenomena, human activities and their interaction, such as landslides, wildland fires, locust plagues, epidemics, transport and dispersal of toxic substances following accidents (nuclear particles, other atmospheric pollutants, marine oil spills) and of volcanic eruption material/ash (especially important for aviation).

The WMO community plays a key role in reducing the impacts of both hydrometeorological and non-hydrometeorological hazards through its collaborative processes and integrated, end-to-end, impact-based forecasting and warning services.


The Tropical Cyclone Programme (TCP) allows tropical cyclone forecasters to access conventional and specialized data/products. This includes NWP products, remotely sensed observations, and forecasting tools on tropical cyclone development, motion, intensification and wind distribution. TCP also establishes national and regionally coordinated systems to ensure that related losses are reduced to a minimum. It works on national and, regional levels through cooperative action, covering activities of Members, WMO regional associations and other international and regional bodies.


WMO Emergency Response Activities use and apply specialized atmospheric transport and dispersion modelling techniques to track and predict the spread of airborne hazardous substances in the event of an environmental emergency. Through this Programme, WMO assists NMHSs, national partner agencies and international organizations to respond effectively to both nuclear and non-nuclear emergencies. These activities rely fully on the GDPFS.


Outreach –WMO Members have developed regional alert platforms such as Meteoalarm ( and global interfaces such as the World Weather Information Service (WWIS) and the Severe Weather Information Centre (SWIC) to increase their outreach. WWIS ( displays official weather observations, forecasts and climatological information for 2 800 cities (as of December 2018). SWIC ( is a single, centralized source for the media and the general public to access official warnings and information on tropical cyclones, heavy rain/snow, thunderstorms, gales and fog. Developed and maintained by the Hong Kong Observatory (HKO). The SWIC website provides or links to advisories issued by RSMCs and Tropical Cyclone Warning Centres, according to current information and warnings. 


Impact-based forecast and warning services – Demand is increasing for interpretative and interactive services from NMHSs, thus their greater focus on impact-based forecast and warning services, an evolution from telling “what the weather will be” to “what the weather will do.” WMO supports its Members in developing state-of-the-art techniques which allow the formulation of easy-to-understand messages upon which immediate action can be taken for the safety of life and property and for the benefit of national economies (WMO, 2015(c)).


Challenges and new societal requirements 

The development and delivery of services that meet societal (national) requirements and address the global challenge lies on three pillars.


An integrated, multi-disciplinary (both natural and social science) Earth system approach– The goals of the WMO Strategic Plan 2020–2030 increase emphasis on integrating all components of the Earth system, including the oceans, the cryosphere, land surfaces, aerosols, and their interactions (European Centre for Medium-Range Weather Forecasts (ECMWF) 2016).

Integrated observations, monitoring, modelling and respective data assimilation frameworks for representing the Earth system are paramount to achieve a seamless analysis and prediction capability. The detailed representation of physical and chemical processes and the coupling of atmosphere, water and land will be integral parts of the models across all targeted scales and forecast ranges. Worldwide collaboration with leading research groups, including the social sciences, is essential. 


Multi-hazard impact-based forecasting and warning services

Timely, reliable early warnings have drastically lowered the number of lives lost due to hydrometeorological events, but socioeconomic costs continue to rise. The continued loss of life and increase in damages is due, in part, to a lack of understanding of impacts and consequences of these hazards. Many NMHSs are therefore moving towards an impact-based multi-hazard forecast and warning approach in which information is imparted with sector- and location-specific impacts that are easy to understand and act on.

Examples include forecasting the possible impact of rainfall on drivers during rush hour or on passengers at an airport due to strong winds. This can be done by working with transportation sector to develop an impact model using vulnerability and exposure datasets, as well as meteorological information. Assessing disaster risk and forecasting impacts are generally beyond the remit of NMHSs but, as risks and impacts are often a result of hydrometeorological events, it may be argued that NMHSs, in partnership with others, are the best equipped to forecast them. 


Promoting end-to-end, people-centred impact-based multi-hazard forecasting and warning systems– NMHSs play a key role in strengthening and maintaining EWS. Governments and many non-governmental organizations (NGOs) have a legal and ethical obligation to protect their citizens and economies by issuing early warnings. The risks from some hazards can be reduced to a tolerable level and their impacts prepared for. Others cannot be eradicated, but awareness of these hazards, their likelihood and the severity of their impacts can be raised. For most threats, a mix of formal and informal warning systems exists – each focussing often on one hazard or a group of similar/related hazards, but operated simultaneously at the level of individuals, communities, businesses, governments and international organizations. Collectively, they provide a first defence against a variety of hazards. 

Understanding the concept and components of MHEWS is a key requirement to develop and strengthen such systems, prioritize investment and international cooperation and measure their effectiveness and progress (Luther et al., 2017). The updated, intergovernmentally agreed definition of EWS contained in the 2016 Terminology on Disaster Risk Reduction (UNISDR–UNGA 2016) is as follows: “An integrated system of hazard monitoring, forecasting and prediction, disaster risk assessment, communication and preparedness activities systems and processes that enables individuals, communities, governments, businesses and others to take timely action to reduce disaster risks in advance of hazardous events”.  This definition is complemented by an annotation that states effective, end-to-end and people-centred EWS include four interrelated key elements (see next illustration). that “need to be coordinated within and across sectors and multiple levels for the system to work effectively and to include a feedback mechanism for continuous improvement. Failure in one component or a lack of coordination across them could lead to the failure of the whole system”. The annotation further explains that “(m)ulti-hazard early warning systems address several hazards and/or impacts of similar or different type in contexts where hazardous events may occur alone, simultaneously, cascadingly or cumulatively over time, and taking into account the potential interrelated effects. A multi-hazard early warning system with the ability to warn of one or more hazards increases the efficiency and consistency of warnings through coordinated and compatible mechanisms and capacities, involving multiple disciplines for updated and accurate hazards identification and monitoring for multiple hazards)” (UNISDR–UNGA 2016).


An Earth system approach to hydrometeorological service delivery

“In the context of weather prediction, the term “Earth system” refers to the Earth’s fluid envelope and interactions with its boundaries. Earth system components such as the atmosphere, the oceans, sea ice and continental land surface have a significant impact on the weather. Modelling their interactions with each other can therefore lead to improved weather forecasts. … ocean modelling, … for example, has led to improved predictions in the medium range, as well as at monthly and seasonal timescales. Taking an Earth system approach means representing the interactions between as many Earth system components as required, at the necessary level of complexity…” (ECMWF, 2016).


Establishing new policies, standards/formats, frameworks and interfaces for sharing/accessing data, products and services– WMO documents and guidance material provide a good basis for the effective delivery of official and authoritative information by NMHSs to the public and relevant stakeholders and for interaction with them. In 2018, the WMO Executive Council requested the development of guides for general service delivery and for integrated urban weather, environment and climate services based on existing guidance material. It further requested that the capacities of NMHSs be strengthened to engage with the health community by collecting and sharing health-related data, impact-based forecast services, and guidance material to improve service delivery as agreed in 2018 in a collaboration framework with the World Health Organization. WMO needs to maintain its primary role as policy, standard, framework developer for key services and their delivery.

As impacts related to hydrometeorological hazards affect an increasingly exposed and vulnerable population and its assets across political boundaries, there is a need for authoritative warnings and alerts from all countries to be made more easily accessible in a timely manner. Moreover, they need to be understandable for decision makers at all levels, including those from the United Nations and humanitarian agencies and the general public, to maximise their value and usefulness. Therefore, WMO is strengthening the capacity to aggregate warning and impact-related information at national, regional and global levels.


The way forward and expected benefits

Authoritative warnings and alerts need to be made more readily accessible and understandable to maximize their value and usefulness to exposed and vulnerable populations and assets. WMO is strengthening capacity to generate and deliver high-quality services, including warnings that contain impact-related information and that can be aggregated on regional and global levels. A more integrated infrastructure and multi-disciplinary – both natural and social science – approach will enhance capacity to improve observations, data processing, forecasting and dissemination/communication within MHEWS. It will benefit existing collaborative WMO initiatives in infrastructure, policy, advocacy, outreach and capacity development and allow for the provision of sound data and information so that Members can generate and deliver harmonized services. The concept of MHEWS is a practical example of seamless service delivery that needs to be based on enablers such as sound governance, standards, partnerships and global and regional support frameworks.

The provision of such services to an ever-growing variety of users in the context of a fast changing and globalized world relies on sound science and infrastructure capacities but also on organization and coordination, product and service design, participatory approaches, coordination and collaboration with research and the private sector. This is particularly true for services to the general public – especially the most vulnerable – and for disaster-risk reduction stakeholders. Such services need to be specifically tailored to national policies and legislation in a systematic fashion. New efforts therefore include approaches such as the proposed GMAS or a WMO Coordination Mechanism (WCM) to support humanitarian activities, and scale up good practices of Members.

The first long-term goal of the WMO Strategic Plan 2020–2030  is to enhance capabilities of Members to develop, access and use accurate, reliable and fit-for-purpose services to best support policymaking and actions to implement the WMO Vision 2030. The four Strategic Objectives under this Goal all highlight services – with particular focus on early warnings – related to hydrometeorological phenomena and for a wide range of applications.

The ongoing reform of WMO constituent bodies aligns with the WMO Strategic Plan 2020–2030 in order to facilitate achieving its goals. The new Commission for Weather, Climate, Water and Related Environmental Services and Applications would contribute to the development and implementation of harmonized services and applications to enable informed decision-making. The new structure will allow for mainstreaming expertise in the long term within thematic standing committees, while also benefiting from the flexibility and responsiveness of temporary study groups to address new challenges and opportunities as they appear. Members’ concerns will be shared and collectively addressed in a systematic, timely, effective and efficient manner. It will help NMHSs to increase their sustainability and relevance.

Smart and fit-for-purpose services should be for all people – all ages, genders, nationalities, the disabled, minorities, etc. All sectors and application areas, all timescales, all spatial scales and all geographical areas, including urban, polar, mountains and coasts will complement each other in order to augment the quality and delivery of services.


A Global Multi-Hazard Alert System

The proposed WMO Global Multi-hazard Alert System (GMAS) is poised to be the WMO framework for substantially increasing and enhancing the availability of, and access to, authoritative warnings and information related to high-impact weather, water and climate events. Its vision intends GMAS to be a highly visible and accessible resource for official warnings and a and driver and vehicle for capacity development and sharing of good practices; efficient outreach to those at risk and to decision-makers; improved visibility and recognition of national alerting authorities (including NMHSs) by key national, regional and global users and stakeholders (taking into account global mobility); and harmonization and standardization of warnings and cross-border cooperation. It would also inform investments by development partners.

GMAS would have organizational and technical elements that build on existing and future WMO mechanisms and infrastructure, recognizing and highlighting the ownership of Members. The GMAS concept, in development at WMO, will align with the roles and functions of the centres that make up GDPFS. It could be built on the alert hub technology, prototyped by the U.S. National Oceanic and Atmospheric Administration (NOAA) Big Data Project. It would leverage WIS to maintain a repository of official warnings, alerts and related information and to distribute this information to authorized users. The use of WIS will ensure that there are no costs for NMHSs. GMAS would further leverage existing subregional and regional warning mechanisms and platforms, as well as the afore-mentioned demonstration projects.

WWIS and SWIC would be the core components of GMAS. They would be developed further to provide a web-based user interface with a map display, ensuring the attribution of information to WMO and NMHSs. This module is being developed by HKO. The Worldwide Met-Ocean Information and Warning Service (WWMIWS) web portal hosted by Météo-France, aimed at shipping users, already provides many of the functionalities included in the GMAS concept in a simple, low-cost but effective manner.

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