The 16th WMO Congress (2011) approved a number of significant changes to the standard procedures for verification of deterministic NWP products, as recommended by CBS-Ext.(2010). The updated procedures will make the results more consistent and relevant for current NWP.
LC-DNV coordinates and facilitates the transition to the updated procedures. All GDPFS centres are encouraged to read the information and guidance provided and to implement these changes as soon as possible.
- Updated verification procedures:
- Manual on the Global Data-processing and Forecasting System: Annex IV to the WMO Technical Regulations (available from WMO library at https://library.wmo.int/opac/index.php?lvl=notice_display&id=12793#.Wo8mHa0pFrk), appendix 2.2.34.
- Implementation guidelines (the document in preparation).
- Lead Centre guidelines for data exchange:
- Auxiliary data: climatology fields and station lists
Main changes
The main changes to the verification procedures are:
- an increase in resolution of the grid used for verification from 2.5°x2.5° to 1.5°x1.5°
- use of a defined interpolation method to retain features at the scale of the verifying grid but not introduce additional smoothing
- use of a common climatology for anomaly correlation (available from the LC-DNV)
- introduction of additional scores to measure forecast activity
It is important that all centres implement these changes to ensure that exchanged scores are as consistent and relevant for current NWP as possible.
Additional changes include:
- additional scores to measure forecast activity
- scores for humidity verification
- additional forecast time steps
- request for daily scores (to allow computation of confidence intervals)
Details of the verification procedures can be found in Appendix 2.2.34 of Manual on the Global Data-processing and Forecasting System: Annex IV to the WMO Technical Regulations. Implementation details can be found here among the Lead Centre documents (the document in preparation). Centres are recommended to consider these proposals when implementing the new verification procedures.
The procedure to exchange the verification results between centres has changed as well. The previous email exchange has been replaced by an ftp exchange provided by the LC-DNV. The data format for verification reports is changed to a new format coordinated by the LC-DNV.
The status of implementation of updated procedures in participating centres is available in a table maintained by the LC-DNV.