WEATHER FORECASTING

Taranaki Daily News, 21 November 1932, Page 9

WEATHER FORECASTING

DR. KIDSON IN TARANAKI. VALUE OF NEW ZEALAND SERVICE. Dr. E. Kidson, Government Meteorologist, has spent a few days in Taranaki to inspect weather and rainfall recording stations. On Saturday morning he visited the New Plymouth -observation centre at the residence of Mr. G. H. Dolby, also the stations of Messrs. W. B. Fussell (Waiongona), C. Jordan (Mangorei) and Shepherd and Jemison (Upper Mangorei). Yesterday he went on as far northwards as Te Kuiti. While at New Plymouth Dr. Kidson made some interesting comments on the service. There were throughout New Zealand, he said, about 450 people who kept rainfall records .only, and 45 stations recording temperatures, wind, rain, etc.

At Wellington every morning the meteorological office received reports by telegraph or wireless from 50 New Zealand stations, mainly post offices or lighthouses. These gave the barometric pressure, temperature, wind force and direction, together with the state of the sea and tides. From this information isobars, or lines connecting places of equal barometric pressure, were plotted on a special chart. The reports received were amplified later in the morning by others from outlying islands, such as Norfolk, Lord Howe and the Chathams. About 12 stations in Australia also reported, but of these only one or two were available in time to be considered in the preparation, of the forecast issued at midday. Further reports were received from ships, mostly up to 3 p.m., and 'it was because all information could be collated by then that 3.30 p.m. was chosen as the time at which the special forecast was issued for the benefit of farmers and broadcast from 2YA. In the preparation of this special forecast the meteorologists tried to look as far ahead as possible, whereas in those issued, at noon and 5 p.m. each day the object was to foretell the weather for the next 24 hours as accurately as possible. . , Dr. Kidson went on to explain that in the temperate regions of the southern hemisphere ther£ was a continuous progression of weather systems from west to east, almost without exception. It was because of this that reports from Australia and ships in the Tasman Sea were of so much value. These systems, of course, developed or changed in character as they moved along. At irregular intervals, also, storms of tropical origin came from the north or north-west. In many instances these started from a north-easterly direction and then veered round. These were amongst the most difficult to forecast, but the office received considerable assistance from ships at sea and the reports from the various islands. In the tropics these storms were usually of small dimensions but extreme violence. As they moved south they became more spread out and less violent, but nevertheless provided some of New Zealand’s heaviest rain, particularly in the eastern districts.

Weather forecasts were used more by farmers than by town-dwellers. They were useful to hay-makers,'also sheepfarmers, for if the latter had co turn out newly shorn sheep into the-rain, particularly cold rain, they were liable to lose hundreds in a single night. Knowledge ■of impending conditions was also valuable to mariners. It was important that they should know the state of the weather along the coasts which they were approaching. Again, some ports could not be worked in certain types of weather, so that vessels might decide to omit their call there. In the case of a boat approaching New Zealand, if the captain was informed that head winds were likely to develop he would probably increase his speed so that he might arrive on schedule. A delay of a few hours might mean the loss of a whole working day, ihe missing by the passengers of their train connections, and. so on. Data concerning annual rainfall were useful to many people. The amount of rainfall to a large extent determined the value of farming land. Such figures also helped to explain fluctuations in production, and other variations.

Engineers used the figures for numerous purposes. If they were bridging a river a study of the rainfall conditions in the river’s watershed enabled them to form some idea of the frequency and volume of floods. Similarly, they enabled an engineer building a drainage system to calculate the* biggest volume of water his pipes would need to carry. Hydroelectric schemes were more interested in the lowest level to which a stream was likely to fall. Information, about temperature was sought by various commercial concerns.' It was taken into consideration in modem' methods of heating buildings. Cool storage authorities made use of the data and they also concerned those manufacturing perishable articles of food.