So far it has proved impossible to provide accurate forecasting beyond about 2 weeks. The next scale is the seasonal outlook that predicts the chance of rain over a 3 month period. No major public forecasting organisation provides any forecast for a period longer than this, although most are working towards it.

There are a number of parameters that can help indicate what the chances are for receiving the rainfall you need in the coming season. Most of these parameters look at the chances of moisture being present in the atmosphere at a level that could produce useful rain.

This Primefact includes information on:

• Bureau of Meteorology seasonal outlook;
• QDPI/QDNR SOI correlation map;
• ECMWF East Asia zone outlook;
• International Research Institute for Climate Prediction;
• Southern Oscillation Index and sea surface temperatures.