Delft-FEWS#

veriflow can be used to verify Delft-FEWS simulations and forecasts. This page describes how to configure veriflow for this purpose.

There are three main use cases for using veriflow with Delft-FEWS:

  1. Running veriflow as a standalone tool

  2. Running veriflow as part of a Delft-FEWS workflow

  3. Setting up a verification dashboard in Delft-FEWS

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Running veriflow as a standalone tool#

This approach is used to verify existing simulations and forecasts that have already been produced within Delft-FEWS. This is the most easy and straightforward way to start verifying Delft-FEWS simulations and forecasts. Anyone with access to the Delft-FEWS PI webservice can use this approach to verify simulations and forecasts that are stored in Delft-FEWS.

Requirements for running veriflow as a standalone tool:

  • ✅ A Python environment with veriflow installed

  • ✅ A veriflow configuration file that specifies the verification settings.

  • ✅ A local or remote connection to the Delft-FEWS PI webservice (version 2025.1 or later), with data available that you want to verify.

  • ✅ Credentials to access the Delft-FEWS PI webservice should be available as environment variables. See the API docs for details on which environment variables to set. Once set, you do not need to configure the credentials explicitly in the veriflow configuration file, veriflow will automatically pick them up from the environment variables.

  • ✅ In your Delft-FEWS system, make sure to set EXPORT_FOLDER_PROCESS_DATA as a global property, it is needed to export NetCDF files from the PI webservice.

Notes

  • Because veriflow will export data from the PI webservice in NetCDF format, and NetCDF format adheres to the CF (Climate and Forecast) metadata conventions, parameters in Delft-FEWS that contain a . will be replaced by a _. Optionally, you can configure the export_id_map in the veriflow configuration, to specify custom mappings from Delft-FEWS parameter names to veriflow parameter names. See the API docs for details on how to configure the export_id_map.

Known challenges

  • As one might expect, the configured lead times in veriflow are always relative to the t0 of a forecast (also known as: analysis_time, forecast_reference_time). When retrieving forecast data where the t0 is offset from the actual data, it is important to take this into account when configuring the lead times in veriflow

Running veriflow as part of a Delft-FEWS workflow#

Not available yet, but expected to be implemented in 2026.

The approach will likely involve exporting NetCDF files from the Delft-FEWS General Adapter and then using veriflow to verify those files as they are produced. This will allow for real-time verification of simulations and forecasts as they are generated by Delft-FEWS. Results can then be imported into Delft-FEWS either by importing the results as Delft-FEWS TimeSeries or by importing images/reports of the verification results into Delft-FEWS for visualization. Importing data back into Delft-FEWS is currently not recommended, as it is not yet clear how to best do this in a way that is scalable and maintainable. We are actively exploring options for this, and welcome any suggestions or contributions.

(Verificatie operationeel in FEWS) (Verificatie langere termijn, gebruik makend van het archief)

Delft-FEWS verification dashboard#

Not available yet.

In this set-up, veriflow would be used to produce verification results that are then visualized the Delft-FEWS Web Operator Client. This would allow users to easily access and explore the verification results directly within the Delft-FEWS interface. We are actively exploring options for this, and welcome any suggestions or contributions.