WMO Initiative for the Global Exchange of Radar Data

WMO has long regarded weather radar as an advanced and invaluable observing system supporting the World Weather Watch Programme and a multitude of meteorological and other applications protecting lives and property affected by local severe weather phenomena. Answering an increasingly urgent and emerging need to address the requirement for access to radar data and products by Numerical Weather Prediction (NWP), hydrological and climate applications, the WMO organized a workshop dedicated to the regional and global exchange of weather radar data. The workshop was arranged with the approval and support of the WMO Commission for Basic Systems (CBS), Open Programme Area Group on Integrated Observing Systems (OPAG-IOS) and took place over 24-26 April in Exeter, United Kingdom, with 18 participants from around the world representing radar operators, data users and data exchange experts.

The workshop considered current and future requirements of weather radar data by reviewing the requirements of WMO Applications Areas currently documented within the WMO Observing Systems Capabilities Analysis and Review Tool (OSCAR) and also by specifically requesting the input of regional and global NWP and the hydrological and climate communities on their current and likely future requirements for weather radar data. NWP requirements and current uses of radar were found to be varied, for example, ECMWF's model assimilates US composite precipitation rate products, while Météo France assimilates polar reflectivities from the French network in the AROME model. An important signal from both the climate and hydrological communities was an emphasis on the importance of facilitating archival of and access to data outside real-time frameworks. Overall, it was made clear that meteorological data users and application areas would derive significant benefit from a wider and internationally standardized approach to radar data exchange and data management and availability.

The workshop reviewed the current status of regional and global data exchange activities relating to weather radar systems and networks, including an (incomplete) assessment of the relative maturity and successfulness of existing exchange mechanisms. Data exchange, mostly of higher-order radar data products is already occurring in most WMO Regions (and in some place between Regions) using a wide range of file formats. Polar radar data are exchanged only in a few places - most notably, within the network of European national meteorological services (EUMETNET) community. Data and products are exchanged both passively and actively using a range of different techniques. The review of the current data exchange models in operation (both of radar and other observing systems) highlighted the challenges, the strengths, the weaknesses and their respective suitability for wider adoption as potential international solutions and standards.

The participants also undertook a review and analysis of the regional perspective of the constraints and barriers to increased weather radar data exchange including both the technical and political elements and, in response, determined opportunities that may exist to overcome these barriers. Willingness and agreement to exchange radar-based information is mostly regulated through bilateral agreements, although multilateral exchange agreements also exist.

An important outcome of the Workshop was the recommendation that a Task Team should be formed within CBS to have the responsibility for coordination, development and finalization of agreed and approved standards for the international exchange of weather radar data. The task team would take into consideration the great progress achieved by EUMETNET in harmonizing operationally, real-time exchanged weather radar data under its Operational Programme for the Exchange of Weather Radar Information (OPERA), recognizing the advanced status and success of the data exchange model and mechanisms already established under that program.

Finally, the workshop also considered existing and identified possible new pilot projects or studies that might be supported by WMO and its Members as a way of promoting, furthering and improving international and regional exchange of weather radar data.