Climate change projections indicate that south-west Australia (SWWA) will experience a drying climate with declining growing season rainfall and rising temperatures. However, seasonal variability will remain the dominant driver of adaptation at the farm level. Forecasts of seasonal rainfall made at managerially relevant times of year should enable farmers to modify farm management to maximise returns in good seasons and minimise losses in bad seasons. However, current use of seasonal forecasts is limited by perceived low levels of skill and limited availability of long-lead forecasts at appropriate times of year.
We present a system for forecasting growing season rainfall in SWWA that uses novel predictors derived from global climate data within sophisticated statistical models. The predictors have been selected based on measurable relationships with SWWA rainfall. The forecasts take the form of probability distributions that describe the most likely rainfall total as well as the predicted variability around it
