Long Paddock - SeasonalClimateOutlook>RainfallProbability

page regenerated:
03 Jul 2009

Seasonal Climate Outlook

TheLongPaddock > SeasonalClimateOutlook > RainfallProbability

Rainfall Probabilities based on
'Phases' of the Southern Oscillation Index
(Stone, R.C., Hammer, G.L. and Marcussen, T.)

Recent trends in the Southern Oscillation Index (SOI) can be used to calculate more accurately the probabilities of receiving particular amounts of rainfall at a particular location; over the next few months.The phases of the SOI were defined by Dr Roger Stone then of QDPI, who used a statistical technique (cluster analysis) to group all sequential two-month pairs of the SOI (from 1882 to 1991) into five clusters (see legend below & help on use of trends in the SOI).

By using this information we have constructed maps of future rainfall probability.

Reference for the SOI Phase system: Stone, R.C., Hammer, G.L and Marcussen, T. (1996) Prediction of global rainfall probabilities using phases of the Southern Oscillation Index. Nature, 384, 252-255.

Phases of the Southern Oscillation Index
	Consistently negative (phase 1)
	Consistently positive (phase 2)
	Rapidly falling (phase 3)
	Rapidly rising (phase 4)
	Consistently near zero (phase 5)

Maps for the all five SOI phases:

[ConsistentlyNearZero] [ConsistentlyNegative] [ConsistentlyPositive] [RapidlyFalling] [RapidlyRising]

Maps for the current three month period using the latest phase:

phase 5

Chance of exceeding median rainfall in the period from July through September based on a Consistently near zero SOI phase over May and June

Graphics in GIF format, each image will appear in a new window.

Australia (updated 14:30, 3 Jul 2009)
Queensland (updated 14:30, 3 Jul 2009)
World (updated 14:30, 3 Jul 2009)

Acrobat document(s). You may need to download the free Adobe Acrobat Reader.

Australia (178Kb) (updated 14:30, 3 Jul 2009)
Queensland (79Kb) (updated 14:30, 3 Jul 2009)
World (986Kb) (updated 14:30, 3 Jul 2009)

Years in history with the same SOI phase over May-Jun:

1878, 1881, 1890, 1891, 1894, 1895, 1898, 1899, 1907, 1908, 1913, 1915, 1919, 1923, 1925, 1926, 1927, 1928, 1932, 1935, 1936, 1937, 1939, 1944, 1954, 1960, 1961, 1969, 1976, 1979, 1980, 1991, 1995, 1999, 2009

what is: "Seasonal Climate Outlook" ?

The term "Seasonal Climate" refers to what the weather was, is, is-likely-to-be for a particular season. The "Outlook" is based on the Southern Oscillation Index (SOI), Sea-Surface Temperature (SST) patterns in the Pacific Ocean are also important in driving climate variability and are useful guides to potential climate patterns in Australia (and other parts of the world too). One rainfall probability system used in Queensland is the "SOI Phase System", the current "Outlook Message" gives commentary on the seasonal outlook and additional information may be found at the Queensland Climate Change Centre of Excellence. You will also find the "Winter Crop Outlook" on the Department of Primary Industries web site.