The Rolling Review of Requirements process

Using the Rolling Review of Requirements (RRR) process defined by the Manual on the Global Observing System (WMO-No. 544) (Part II, Requirements for observational data), user requirements for observations are compared with the capabilities of present and planned observing systems.

User requirements are collated in a comprehensive, systematic and quantitative way in the WMO Observing Requirements database, which attempts to capture observational requirements to meet the needs of all WMO programmes.

The comparison of user requirements with observing system capabilities for a given application area is called a Critical Review. The output of this is reviewed by experts in the relevant application and used to prepare a Statement of Guidance (SOG), the main aim of which is to draw attention to the most important gaps between user requirements and observing system capabilities, in the context of the application. A wide range of applications within WMO programmes have already been addressed.

A more detailed description of the Rolling Requirements Review process is available for download (pdf)


Statements of Guidance (SOG)

For each of the application areas considered, the SOG provides an assessment of the adequacy of observations to fulfill requirements and suggests areas of progress towards improved use of space-based and surface-based observing systems. Only the most significant variables in a given application area have been analyzed in the SOGs.


Applications area

Contact point

Date of approval


Global NWP

Erik Andersson (ECMWF)

May 2012


High Resolution NWP

Thibaut Montmerle (France)

May 2012


Nowcasting and Very Short Range Forecasting (see note 1 below)

Aurora Bell (Romania)

May 2012


Seasonal to Inter-annual Forecasts

Laura Ferranti (ECMWF)

May 2012


Aeronautical Meteorology

Jitze van der Meulen (Netherlands)

May 2012


Atmospheric Chemistry

Oksana Tarasova (WMO)

Dec 2005


Ocean Applications

Ali Mafimbo (Kenya)

May 2012


Agricultural Meteorology

Robert Stefanski (WMO)

June 2011



Wolfgang Grabs (WMO)

July 2008


Climate Monitoring (GCOS)
The following GCOS reports are considered as SOG :

GCOS Secretariat (GCOSJPO[at]



Climate Applications (Other aspects, addressed by the Commission for Climatology)

William Wright (Australia)

May 2012


Space Weather

Terry Onsager (USA)

May 2012

Although not formally an Application Area, the requirements for Global Cryosphere Watch (GCW) are split between all other Applications Areas. CBS is still discussing the status of the GCW within the Rolling Review of Requirements. For the time being, Mr Barry Goodison (WMO Secretariat) is acting as focal point for the GCW.The following GCW documents shall be noted:

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