Fig. 1: KNMI earthquake data visualized in the test version of the BES extranet. The panel shows earthquakes in the region around Saba and St. Eustatius. Colors indicate the time since the earthquake happened, the number is the earthquake magnitude.
Jelle Assink and Elske de Zeeuw – van Dalfsen, KNMI
Early Warning Centre (EWC) at KNMI
Since 2025, KNMI operates as an Early Warning Centre (EWC). The goal of the EWC is to provide timely, independent and adequate information on meteorological and geophysical hazards, and evaluate risks, consequences and impact with particular attention to multi-hazard events with cascading or compounding effects.
The extranet platform
KNMI has developed platforms to support the timely and effective relay of meteorological and geophysical warning information to professional stakeholders both internal and external to KNMI, in support of the EWC program goals. For external stakeholders, the so-called extranet platform has been designed. This development represents an important step forward strengthening risk preparedness and environmental monitoring for the Caribbean Netherlands, specifically the islands of Bonaire, St. Eustatius, and Saba.
A Purpose-Built Platform for External Stakeholders
This secure online environment has been developed with the needs of professional stakeholders in mind—those who rely on early, accurate, and accessible information to guide operational decisions. Whether supporting emergency response, aviation safety, infrastructure protection, or public communication, the extranet will offer direct access to environmental data and warnings issued by KNMI (Fig.1).
Meteorological and Geophysical datasets
The extranet brings together multiple hazard domains in a single interface. A first demonstrator implementation for the Caribbean Netherlands includes:
- Tropical Storm Warnings: Official warnings issued in coordination with NOAA’s National Hurricane Center (NHC), tailored for the local context.
- Weather Forecasts and Warnings: Visualized model data layers and textual summaries to support marine safety and coastal management (wind, temperature, precipitation, thunderstorms, visibility).
- Seismological Events: Rapidly updated information on regional seismic activity, including automatic event listings and maps.
These elements form a cohesive information environment to help users anticipate and respond to evolving natural hazards.
Future work will, amongst others, focus on:
- Volcano monitoring using the seismic and GNSS network on Saba and St. Eustatius and provision of warnings
- Tsunami warnings, in coordination with the Pacific Tsunami Warning Centre (PTWC).
Fig. 2: KNMI weathermodel data visualized in the test version of the BES extranet showing temperature and rainfall in the region around Saba and St. Eustatius.
Technical framework for combining multiple datasets
One of the technical strengths of the platform lies in its ability to operate with standardized API calls. For example, it is possible to ingest WMS (Web Map Service) layers from both internal KNMI and external databases. This integration ensures that spatial data—such as forecast models or observational overlays—can be presented in a dynamic, map-based format that supports both quick overviews and deeper analysis. It also lays the groundwork for future scalability as new products or hazard types are added. Finally, this implementation facilitates multi-hazard analysis since multiple data-types can be easily visualized without detailed technical knowledge.
Access and Next Steps
The Caribbean extranet demonstrator marks one of the first deployments of this extranet framework. The idea is to further improve the extranet design together with the intended users in order to work towards an operational product.
