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. Volume I - Global Aspects WMO-No.485 (2010 Edition - Updated in 2012), http://www.wmo.int/pages/prog/www/DPFS/Manual_GDPFS.html (Part II, Attachment II.7, Table F).
  • Updated verification procedures, approved by CBS, to be included in the Manual of GDPFS; document provided by LC-DNV
• Lead Centre guidelines for data exchange:
  • Procedure for posting verification reports to FTP server
  • Data format of verification reports
  • Access to FTP site
• 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 updated verification procedures can be found in Part II, Attachment II.7, Table F of Manual on the Global Data Processing and Forecasting System, Volume I - Global Aspects. Update of verification procedures which has been approved by CBS will be included in the Manual of GDPFS. The text of updated procedures can be found here.

The procedure to exchange the verification results between centres is changed. The current email exchange is 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.