An assessment of the 5 phase SOI climate forecasting system to improve harvest management decisions

Extreme rainfall events during the harvest season can cause major disruptions to harvesting operations. Of critical importance is unseasonably high rainfall in the May-June and October-November periods which affect crush start time, timing of sugar supply, harvest season length and ratooning capability for the following season. If the likely climate conditions for these periods can be forecast with a reasonable degree of certainty, and with sufficient lead times, then local industry decision makers can better plan harvesting operations to coincide with the likely forecast, and thereby reduce the risk and uncertainty associated with start and finish times of the harvest season. The aim of this paper is to investigate the potential usefulness of the climate forecasting system that incorporates the 5 phases of the Southern Oscillation Index (SOl) in aiding decision making capability and risk management associated with harvesting operations. Interaction with the sugar industry indicated a clear need to identify critical 'wetday' occurrence. The likelihood of wetdays occurring during May-June and October-November were calculated using the '5 phase SOL system'. Results from this analysis indicate that this climate forecast system offers some benefits associated with forecasting 'wetdays' during October-November, whereas benefits associated with forecasting 'wetdays' during May-June are currently more limited. The usefulness of the climate forecast was found to vary with lead-time and location