Seasonal Climate Outlook Message for October to January 2006

The bottom line

Pacific Ocean SST Patterns Remain Neutral 24/10/05

According to information from the Bureau of Meteorology "El Niño wrap up" at www.bom.gov.au/ the key indicators of the SOI, trade winds and sea surface temperatures (SST) confirm the persistence of a neutral sea surface temperature and climate pattern in the Pacific. This pattern would therefore be unlikely to change before the end of the year.

In terms of output from 12 surveyed reputable ocean or coupled ocean/atmosphere forecast models, all 12 are showing a continuing neutral SST pattern through to March next year. For more information on conditions in the Pacific try the US Climate Prediction Centre at www.cpc.ncep.noaa.gov/

The number of drought declared shires in Queensland has remained steady. As of the 30th September there were 61 shires and 7-part shires drought declared under State government drought processes. This is approximately 60.6% of the land area of the State. There are also 113 Individually Droughted Properties (IDPs) in a further 16 shires. As well there is a Commonwealth Government Exceptional Circumstances Declaration covering 55.6% of the state.

Information regarding drought declarations can be obtained from your local DPI Stock Inspector or the Rural Risk Strategies Unit. The unit can be contacted through the DPI&F Call Centre on 132523 or on (07) 3239 3181. For a full list of drought declared shires and the latest seasonal conditions report go to www.longpaddock.qld.gov.au/

Changes in SST patterns in the Pacific along the equator from the west coast of South America to around the International Dateline drive changes in the global circulation patterns that influence our local climate. The SOI is a useful way of measuring these changes. The SOI is simply a measure of the difference in barometric air pressure between Darwin and Tahiti. It typically ranges in value from plus 30 to minus 30. While measured on a daily basis, it is the shift in value of the SOI on a monthly basis that is considered as a reflection of SST patterns and strength of the Walker Circulation.

By analysing the SOI phases and historical climate data (rainfall, frost, hail, temperature etc), a relationship can be developed to indicate for example, whether the coming three months is likely to be wetter or drier than normal. This relationship can also be used to investigate the chance of extreme climate events.

It is worth noting that the SOI influence on climate varies across Australia (usually greatest skill is for eastern half of Australia) and between seasons (usually greatest skill is for winter, spring and early to mid summer). Users of the SOI are urged to investigate the relationship for their location by using such tools as Rainman StreamFlow.

As of the 24th October the 30-day average of the SOI is plus 9.9. Daily updates on the SOI are available on (07) 46881439. For more information contact the DPI&F Call Centre on 13 25 23.

Last updated: 24 October 2005