Early warning systems

Climate impacts
Droughts, Extreme temperatures and heatwaves, Flooding, Heavy rains, Sea level rise, Storms, Wildfire
Cross-sector, Disaster Risk Reduction
IPCC category
Social: Informational, Structural and physical: Technological options


Early warning systems (EWS) are usually key elements of climate change adaptation and disaster risk reduction, and aim to avoid or reduce the damages caused by hazards. To be effective, EWS need to actively involve the people and communities at risk from a range of hazards, facilitate public education and awareness of risks, disseminate messages and warnings efficiently, and ensure that there is a constant state of preparedness and that early action is enabled. In Europe there is a considerable experience with early warning systems, especially as concerns risks related to floods and flash-floods, storms, forest fires, heatwaves and droughts. Some EWS provide services and products for more than a specific climate-related risk, others focus on specific climate-related risks and/or sectors. Activities of accurate monitoring, modelling and forecasting of climate variables are essential to provide reliable data feeding the warning systems.

Copernicus Emergency Management Service (Copernicus EMS) uses satellite imagery and other geospatial data providing information for emergency response in relation to different types of disasters, including climate related hazards. It includes a mapping component and an early warning and monitoring component for floods, droughts and forest fires.

Meteoalarm provides the most relevant information needed to prepare for extreme weather (e.g. heavy rain with risk of flooding, severe thunderstorms, heatwaves, forest fires, coastal tides) expected to occur across Europe. A prototype of heat health early warning system for Europe (European Heat Health System) is being prepared within the project H2020 Blue-Action as an epidemiological surveillance tool aimed at contributing to a better monitoring and forecasting system of temperature-related health risks supporting public health management and decision making.

Besides these large-scale initiatives, EWS have also been designed and implemented at lower scales (regional, national, sub-national and local) with several examples in the Adriatic-Ionian region. The Meteorological and Hydrological Service of Croatia (DHMZ) provides EWS for natural hazards (alert for severe weather conditions, strong winds, possibility of thunderstorms, extremely high and extremely low air temperatures, intensive precipitation, river floods, droughts, fires in open spaces, and fogs). There is however a growing need for EWS regarding sea floods. Such EWS would need to include more and well positioned wave height measuring instruments (waverider buoys) in the Adriatic.

Moreover, DHMZ is involved in the WMO project “South-East European Multi-Hazard Early Warning Advisory System” (SEE-MHEWS-A), aimed at strengthening regional cooperation in forecasting and early warning, and supporting the involved national services in fulfilling their mandates in order to minimize the impacts of hazardous weather events on people, infrastructure and industry. A sub-national Weather Alert Web Portal has been developed in the Emilia Romagna Region (Italy) in parallel to the development and refinement of real-time hydro-meteorological monitoring technologies and a widespread risk communication programme. A local early warning system for high tide in Venice is operated by the Tidal Forecasting and Early Warning Centre of the Venice Municipality to early advice people about tide events with associated flooding impacts for the city; the frequency of these events is expected to increase in the future due to sea-level rise. Local prototypes of EWS (including one system for the Lido di Dante on the Emilia Romagna coast) were also developed within the MICORE project, for a reliable prediction of coastal morphological impacts due to marine storm events in support of civil protection mitigation strategies.

Funded by the ADRION 2014-2020 program, I-STORMS project has developed joint strategies for ensuring effective response to sea storm emergencies in the Adriatic-Ionian region, also by improving the countries’ capacities on data interoperability, early warning and civil protection procedures. The I-Storm Guidelines for translating data and forecasts to early warning and intervention procedures recognize the key role of online weather, marine and coastal observation networks and forecasts availability, as well as the possibility of sharing real-time data among the countries facing the Adriatic Sea. Within the I-STORMS project, the Sea Storm Atlas was created, drawing the maps of risk characterisation of the ADRION coasts. The aim of this Atlas was to identify the most vulnerable areas, and thus strengthen the common understanding of current challenges regarding sea floods.


Early warning systems are usually considered as cost-effective non-structural measures, though complete cost-benefit analyses are a complex task and are rarely undertaken. According to the Global Assessment Report on Disaster Risk Reduction (2011), costs include the operational cost of the system and its maintenance and progressive improvement, as well as the cost of possible false alarms and the related inappropriate actions. A cost-benefit analysis must also take in consideration the damage and economic saving related to timely action. Cost-benefit depends on the effective reliability of the warning system (and this, in turn, depends on the availability of effective monitoring and forecasting systems and models), and on the hazard frequency distribution.

Warning systems provide benefits and are effective when they are accompanied by the activation of specific measures aimed at saving people, infrastructures and housing (e.g. safe evacuation routes, sheltered areas, activation of flood protection measures, etc.). Early warning systems are basic components of any disaster risk reduction strategy. A successful EWS save lives, infrastructures, land and jobs, and support long-term sustainability. Early warning systems aim at assisting public officials and administrators as well as private sector actors, communities and individuals in their planning, saving money in the long run and protecting economies.


Design and implementation of an early warning system typically require 1 to 5 years, depending of the specific objective and characteristics of the system. The maintenance and improving of an early warning system is a continuous process that is needed to obtain reliable information and reduce uncertainty, avoiding wrong advices as much as possible. The lifetime of EWS is typically long; however it depends on the financing available for the EWS maintenance and updating, as well as for the maintenance of the measurement network and modelling facilities supporting the early warning system.


Climate Adapt Platform

Copernicus Emergency Management Service 

United Nations Climate Action 

GAR, (2011). Cost and benefits of early warning systems