An objective method of forecasting sub-minimum weather conditions at Cambridge Aerodrome, Tasmania

A study has been made of weather conditions at Cambridge Aerodrome, Tasmania, to provide forecasting officers with an aid whereby they may more easily assess whether terminal conditions will be satisfactory, warning or minimum according to the classification of the Department of Civil Aviation. The technique as developed requires, as a preliminary step, forecasting the geostrophic wind speed and direction as well as the dry bulb temperature and dew point, after which the degree of risk can be assessed at nil, slight, moderate or high by using diagrams provided. Slight risk is considered to be an approximate 15% chance of experiencing conditions which are not completely satis-factory for moderate risk this chance is about 55% and for high risk 95%. The diagrams have been prepared empirically but have been tested against an independent set of data with satisfactory results.