WORLD METEOROLOGICAL ORGANIZATION ____________________ Distr.: RESTRICTED CBS/OPAG-IOS (ET AWS-1)/Doc. 2 (20.VIII.2002) _________ COMMISSION FOR BASIC SYSTEMS OPEN PROGRAMME AREA GROUP ON INTEGRATED OBSERVING SYSTEMS ITEM: 1.2 EXPERT TEAM ON REQUIREMENTS OF DATA FROM AUTOMATIC WEATHER STATIONS Original: ENGLISH ONLY FIRST SESSION GENEVA, SWITZERLAND, 2-6 SEPTEMBER 2002 EXPLANATORY MEMORANDUM 1. ORGANIZATION OF THE MEETING 1.1 Opening of the meeting The Meeting of the Expert Team on Requirements of Data from Automatic Weather Stations (ET/AWS) will be opened on Monday, 2 September 2002, at 10:00 a.m. at the WMO Headquarters, Geneva. 1.2 Adoption of the agenda The Meeting will be invited to consider the provisional agenda with a view to its adoption. 1.3 Working arrangements for the meeting The Meeting will agree on details concerning the organization of its work including working hours. The documentation will be available in English only, and the Meeting will be held in English. 2. REPORT OF THE CHAIRMAN The chairman will brief the participants on the purpose and scope of the meeting based on the terms of reference of the Expert Team as well as on the results of the Twelfth Session of CBS (Geneva, 29 November - 8 December 2000). He will also submit a report on the activities carried out by the ET/AWS since CBS-XII according to the Working Plan. 3. REVISED FUNCTIONAL SPECIFICATIONS FOR AUTOMATED WEATHER OBSERVING SYSTEMS FOR BUFR/CREX TABLE DRIVEN CODES The meeting will consider the revised Functional Specifications for Automated Weather Observing Systems for BUFR/CREAX Table Driven Codes after comments received from WMO Technical Commissions and make proposal for CBS-Ext.(2002). 3.1 The BUFR Template for AWS data and new BUFR descriptors The meeting is invited to discuss the BUFR templates and descriptors for surface observation data, including data from AWSs recommended by ET/DR&C (Prague, April 2002) and make recommendations for CBS-Ext.(2002). CBS/OPAG-IOS (ET AWS-1)/Doc. 2, p.2 4. REQUIREMENTS FOR AUTOMATED OBSERVATIONS OF “PRESENT WEATHER”, CLOUDS, WATER VAPOUR AND THE “STATE OF THE GROUND” IN ORDER TO IDENTIFY THE NECESSITY TO DEVELOP OR REFINE QUANTITATIVE DEFINITIONS The meeting is invited to review the list of requirements for automated observations of “present weather”, clouds, water vapour and the “state of the ground” with the view to identify the necessity to develop or refine quantitative definitions. 5. REVIEW AND REFINE PRACTICES FOR REPORTING THE INSTANTANEOUS PRECIPITATION INTENSITY, TOTAL CLOUD AMOUNT AND CLOUD HEIGHT Under this agenda item, the meeting is invited to review a list of recommended measurement practices and a list of proposed new practices for reporting respective variables. 6. SUGGESTIONS ON POSSIBLE REPLACEMENT OF MANUALLY OBSERVED TYPES OF CLOUDS USING AUTOMATED TECHNOLOGY The meeting is invited to review available and near future technology for direct and indirect measurements of clouds and make proposal on replacement manual measurement of clouds by automatic systems. 7. PROPOSALS FOR IMPROVED QUALITY CONTROL PROCEDURES FOR DATA FROM AUTOMATIC WEATHER STATIONS Under this agenda item, the meeting is invited to consider proposal of the new concept of Quality Control Procedures for AWS data and consider the possibility of the validation of checking algorithms. 8. ANY OTHER BUSINESS 8.1 Information on EUMETNET PWS-GTS project Under this agenda item, the meeting is invited to note the activities taken by the EUMETNET and its pilot project for exchange of observations from AWSs using BUFR code. 9. RECOMMENDATIONS TO BE SUBMITTED TO CBS-EXT. (4-12 December 2002) The Meeting is invited to develop recommendations to CBS-Ext.(2002) according to the ET/AWS Work Plan. 10. FUTURE WORK PLAN The Meeting is invited to develop recommendations to CBS-Ext.(2002) regarding the need for ET/AWS continuity and its future work programme. 11. CLOSURE OF THE MEETING It is expected to close the meeting on Friday, 6 September 2002, afternoon.