H—37

The central forecasting office has co-operated with Catchment Boards in the matter of flood warnings. It has been arranged that the forecaster on duty rings the secretaries of certain Catchment Boards whenever heavy rains which may produce flooding are expected in the Boards' areas and subsequently keeps in touch with them until the danger has passed. Many other special services were provided, including forecasts for photographic work for N.Z. Aerial Mapping, Ltd., forecasts for the State Forest Service during periods of fire hazard, and numerous forecasts for haymaking, harvesting, and other farming operations in response to telegraphed inquiries. The total number of separate forecasts issued by the central office during the year was over 23,000. Investigations have been made with a view to improving the accuracy and detail of frost forecasts, but the efforts have been limited by the availability of staff. Coded weather-map analyses were promulgated every six hours by teleprinter for the information of branch offices in New Zealand and at twelve-hourly intervals, by radio, for meteorological services overseas and for ships. The collection and distribution of reports by teleprinter and radio were controlled from the central forecasting office. The communications system was efficiently operated by officers seconded from the Post and Telegraph Department. At Suva, general forecasts for the Fiji area were issued twice daily from the local broadcasting station, ZJV. The Suva office has also been responsible for the initiation of hurricane warnings for the South Pacific area and for the issue of special forecasts as required. Climatology Data used in the compilation of climatological statistics have been collected for many years from a large number of observing stations, the majority of which are maintained by voluntary observers to whom once again I wish to express sincere appreciation of their valuable assistance. During the year 6 new climatological stations were established, located at Kerikeri, Paeroa, Hamilton (Soil Fertility Station, Rukuhia), Musselburgh, Taumarunui, and Aitutaki Airfield. At the end of March, 1947, the total number of such stations under New Zealand control was 99. This figure includes 12 Pacific Island stations, but excludes those based on Fiji and which are being operated on behalf of Fiji and the United Kingdom. Daily readings from these stations include rainfall, temperature, and humidity at 9.30 a.m., together with maximum and minimum temperatures, while certain stations record also barometric pressure, soil temperature, duration of bright sunshine, evaporation, and,run of wind. In addition, about 600 observers record the daily rainfall and forward monthly returns for analysis. Fifty new rainfall stations were established during the year. Additional climatological data is available in the monthly returns received from about 110 synoptic reporting stations, at many of which detailed observations are made as frequently as six times each day. The returns are of special value as a source of cloud, wind, and visability statistics. In close collaboration with the Technical Committee on Hydrologic Data of the Soil Conservation and Rivers Control Council, arrangements are in train to increase the number of rainfall stations to approximately 1,100 (including 100 self-recording gauges). The location of the additional gauges, together with the finding of suitable observers, is being organized in collaboration with the Council and the various Catchment Boards. During the year an endeavour was made to collect rainfall data from hitherto unco-ordinated records maintained by local bodies, private individuals, &c. In response to a number of circulars sent out, we are now being supplied with copies of an additional 112 current records, and received, in addition, a number of back records. The response to this appeal must be considered very satisfactory, and our grateful thanks are due to those who are co-operating with us in the task of assembling all available rainfall data. This Office has undertaken the preparation of a more detailed analysis of all rainfall returns. While the results will be of special value for the Soil Conservation and

31