It is recommended that one's own forecasts be made on the basis first, of official forecasts which are given on the radio and television and in the daily press. These general forecasts may be compared with regional forecasts, where they are given. The amateur forecaster should also take into account certain factors in his own area. These might have a bearing upon local weather conditions. For example, where there are hills and woods they act as a shield against the wind for those who are sheltered by them. A valley may cause the wind to change its course to some degree and perhaps increase its force. Again, a warm moist wind may move over flat country accompanied by only light showers. But when the wind crosses hilly country considerable rain may develop. The amateur weather man studies the area in which he lives, notes its physical features from the point of view that they may have some connexion with the local weather.
Official forecasts and reports in the press are often given together with weather maps. In order to understand the maps the following things should be noted. The positions of weather stations are indicated by small circles, and barometric pressures by numbers. Places which show the same pressure are linked by lines, called isobars. These run near to or might even pass through the stations. Wind direction is indicated by arrows. To these arrows lines may be added representing wind speed. (Refer to the Beaufort Scale for map symbols.) Again, wind speed may be indicated by numbers. Note that for a depression the arrows are turned slightly towards the centre of pressure, and they point in an anti-clockwise direction. For an anticyclone the arrows point outwards from the centre of pressure, in a clockwise direction. When one is looking at a weather map the relative positions of the isobars should be noted. If they are drawn close to one another then wind speed is greater than when they are farther apart. One other thing may be mentioned, namely that among other map symbols which are used are those which represent a warm, a cold, or an occluded front.
On the basis of such official forecasts, plus one's own observations, an attempt may be made to estimate what flying conditions will be like one, two, or more days ahead. As far as local observations are concerned, it is a good plan to make them at fixed times during the day, for example, say 8.30 a.m. and 5.30 p.m. This would provide a regular system for weather study, whereby the following items could be recorded: wind direction and speed; cloud formation; temperature and barometer readings. On the latter point, it will be remembered that a falling barometer is a sign of rainy weather, and a rising barometer, of fine weather.
Flight RecordsMuch pleasure is to be derived from making these and from keeping them for reference. The idea is to set down in a note-book certain comments relating to flights as they are made. The records will be mentioned again in connexion with kite clubs and competitions. In the meantime, the following gives an idea of the kind of thing in mind.
- Date of Flight.
- Base (i.e. place where kite is flown).
- Cloud Formation (see list of cloud types).