The thirteenth session of the Executive Committee of the World Meteorological Organization (WMO) was held in Geneva from May 11 to 30, 1961, under the chairmanship of Mr. A. Viaut, President of the organization. As usual two working committees were set up on: administrative and financial questions, and technical questions. Discussions in plenary were based mainly on the reports of these committees. Following the presentation of reports on the meetings of regional associations and commissions, the report of the working group set up to study the revision of the WMO convention was heard and discussed. General agreement was reached on the substance of amendments proposed for some articles, and a provisional text was submitted to a legal expert for study and report. With regard to the WMO general regulations, it was decided that modifications arising from the proposed amendments to the convention should be studied after the amendments had been approved. The Executive Committee considered reports on the WMO field programs under the UN Expanded Program of Technical Assistance (EPTA) for 1960 and for the period 1961–1962. The need was stressed for field visits, in particular to the newly independent countries, to help them in the assessment of their requirements for technical assistance. Plans for future training seminars under EPTA were discussed and the Committee recognized in particular, in view of the increasing interest in water resources development, the importance of holding training seminars on hydrological forecasting. The Executive Committee also took note of the training seminars—organized in Cairo, Bangkok, and Nicosia and carried out under joint International Civil Aviation Organization (ICAO)-WMO auspices—on forecasting for operations of turbine-engined aircraft.