Towards a single global standard for polar weather radar data representation with FM301 – CfRadial2

Standardized representation of weather radar data is being addressed by the World Meteorological Organization’s (WMO) Joint Expert Team on Operational Weather Radar (JET-OWR) and Task Team on CFNetCDF, starting with the representation of moment data in original polar/spherical coordinates. In April 2021, the WMO’s Infrastructure Commission (INFCOM) approved experimental use of data representation using the Climate and Forecasting (CF) Conventions and the Network Common Form (NetCDF) file format. Two pilot data types were identified for such experiments, one of which is weather radar data. FM301 is the new WMO use of CF and NetCDF, with standardized profiles for each data type. For weather radar moment data, the FM301 profile is CfRadial version 2 (CfRadial2).

In March 2023, the FM301 profile was approved for inclusion in the WMO Manual on Codes by the 76th session of the WMO Executive Council (EC-76). This decision clears the way for FM301 to transition from experimental to operational status. Efforts to support the adoption and use of FM301 are underway under the auspices of the WMO:

1. A software library has been prepared for reading/writing FM301, with the intent of it constituting a reference implementation. This software is being used with radar data in Australia, Canada and the United States to demonstrate its use with, and the natural variability of, radar data from different countries.

2. The use of FM301 with the WMO Information System (WIS) version 2.0 is being investigated. JET-OWR will explore how these data can be best integrated into future WMO data exchange functionality.

3. Guidance on the use of FM301 has been included in Volume VI of the Guide to Operational Weather Radar Best Practices developed by JET-OWR, that was also approved for publication at EC-76. Additional supporting documents such as FM301 migration guides from existing common formats such as ODIM_H5 and CfRadial1 are also under development.

This poster will address the status of FM301 and these ongoing activities.