LIKE most agricultural industries, the Australian sugar industry is exposed to the
elements of the climate. Knowing if the season ahead is likely to be wetter or
drier can assist industry decision makers plan for the future. RAIN
FORECASTER is a computer program that can forecast rainfall and wet days
using phases of the Southern Oscillation Index (SOI) and anomalies in sea
surface temperatures in the Niño 3.4 region which forms part of the central
equatorial Pacific Ocean. RAIN FORECASTER also incorporates the long lead
forecasting model developed by Florida State University (FSU). The Florida
State University model allows industry to assess early in the year (e.g. January,
February) if there is likely to be a wet finish to the harvest season. Whilst RAIN
FORECASTER can be used as an operational prediction tool, it is also a
learning tool that can be used to understand how climate indices influence
rainfall patterns. For example, by experimenting with RAIN FORECASTER,
three key rules emerge common to most sugarcane growing regions located
along the eastern coast of Australia. These rules are: (i) consistently positive SOI
phases and/or negative Niño 3.4 anomalies (La Niña) during the harvest season
favour wetter harvest conditions; (ii) consistently negative SOI phases and/or
positive Niño 3.4 anomalies (El Niño) during the harvest season favour drier
harvest conditions, and (iii) La Niña projections for the harvest season made by
the FSU model early in the year, increase the risk of a wetter finish to the
harvest. RAIN FORECASTER can be used for forecasting conditions outside
the harvest season, but different results may appear for different regions. RAIN
FORECASTER is a simple tool that provides an excellent basis for exploring
how climate conditions are influenced by variations in atmospheric and oceanic
conditions.