Assessing the climate risk for the coming season can help with decision making, particularly with regards to managing inputs. There is a range of information available to growers on the status of El Niño-Southern Oscillation (ENSO), Indian Ocean Dipole (IOD), Southern Annular Mode (SAM) and Madden-Julian Oscillation (MJO).

Seasonal forecasts: rainfall verses temperature
Modelling and simulating rainfall convective processes in various layers of the atmosphere is a challenging science. The accuracy of rainfall seasonal predictions varies throughout the calendar year and by region.
Temperature predictions based on air pressure patterns are more accurate than rainfall forecasts.
Evaporation due to hot temperatures is a vital component of the moisture balance sheet that should not be overlooked.
Above average temperature forecasts can be a good guide to approaching months of heat waves and extreme weather. Conversely models showing below average three-monthly outlooks can also signal increasing cloud cover and lower evaporation, and hopefully rainfall.

El-Niño Southern oscillation index (ENSO)
ENSO is a coupled atmospheric/ocean phenomenon tracking the moisture in the tropical Pacific Ocean. A strongly positive Niño 3.4 index is associated with El Niño (historically dry) events and a strongly negative index is associated with La Niña (historically wet) events. The Southern Oscillation Index (SOI) is an air pressure measurement calculated between Tahiti and Darwin. The SOI represents a 30-day average of a broad belt of air pressure in the Pacific Region. When the SOI is positive (La Niña), mean sea level air pressure is lower, and conditions are historically more favourable for rain.

Indian Ocean Dipole (IOD)
The IOD is a sea surface temperature index in the Indian Ocean. This is a secondary moisture source during the winter and spring seasons in eastern Australia and represents the distribution of the warm ocean currents in the Indian Ocean. A negative IOD value is favourable for moisture supply and cooler spring conditions.

Southern Annular Mode (SAM)
The SAM is a measurement of the mean sea level pressure around latitudes in Antarctica that looks at the difference or ‘gradient’ of the air pressure patterns that can affect daily variations in eastern Australian rainfall and temperatures. The key feature of the SAM is its influence on easterly moisture circulation patterns from the Tasman Sea into eastern Australia, where a positive anomaly allows moisture to feed into inland trough and frontal systems producing rain events. A positive SAM will direct moist, convective air from the Tasman Sea and Coral Sea into frontal activity. The record rainfall received over the Australian continent in 2010 was attributed largely to the sustained positive influence of the SAM on rain-bearing moisture circulation patterns. A negative SAM has also been found to reduce the number of cold fronts that originate from the Southern Ocean, resulting in a dry, stable westerly air pressure pattern.

The Madden-Julian Oscillation (MJO)
The MJO is a tropical disturbance that propagates eastward around the global tropics with a cycle in the order of 30–60 days. The MJO has wide ranging impacts on the patterns of tropical and extratropical precipitation, atmospheric circulation, and surface temperature around the global tropics and subtropics. The MJO is often variable, with periods of moderate-to-strong activity followed by periods of little or no activity. The MJO affects the Australian continent from November to April. Although studies have shown the MJO has a stronger connection with rainfall in more northern cotton areas, a passing MJO can also unsettle often stable circulation patterns and lead to a change in southern growing areas  With climate scientists anticipating tropical influences to shift further south in future, the MJO may have even more impact through central-eastern Australia. See the MJO CottonInfo YouTube explainer video at youtu.be/TXab5n3HxHA