|Southeastern Aust Seasonal Rainfall Outlook: probabilities for Spring 2009, issued 26th August 2009|
Drier spring favoured over much of SE Australia
For southeastern Australia, the outlook for total rainfall for spring (September and November) shows a moderate to strong shift in the odds favouring drier conditions over most of SA, Victoria, Tasmania and southwestern NSW. Only the northern half of NSW and northeastern part of SA show no strong shift favouring either wetter or drier conditions.
The pattern of seasonal rainfall odds across SE Australia is a result of recent warm conditions in the Pacific Oceans (El Niño).
During spring (September to November), the chance of exceeding
New: An expanded set of seasonal rainfall outlook maps and tables, including the probabilities of seasonal rainfall exceeding given totals (e.g. 200 mm), is available on the "Water and the Land" (WATL) part of the Bureau's website.
Outlook confidence is related to how consistently the Pacific and Indian Oceans affect Australian rainfall. During spring (September to November), history shows confidence to be moderately consistent over southern and northeastern SA, most of NSW and Victoria and northern Tasmania. Over the remaining areas, especially western SA and southern Tasmania, the effect is only weakly to very weakly consistent. In these areas where outlook confidence is not high (especially central SA), caution should be used when interpreting these outlooks (see background information).
An El Niño event looks to be developing across the Pacific: the latest outputs from computer models indicate it will reach peak intensity late in the year. El Niño events are usually (but not always) associated with below normal rainfall in the second half of the year across large parts of southern and inland eastern Australia. The SOI is approximately −7 for the 30 days ending 23 August. For routine updates and comprehensive discussion on any developments please see the ENSO Wrap-Up.
Click on the map above for a larger version of the map. Use the reload/refresh button to ensure the latest forecast map is displayed. More detailed forecast maps, including the probabilities of seasonal rainfall exceeding given totals, can be found here.
More information on this outlook is available Monday to Friday from 9.00am to 5.00pm local time by contacting the Bureau's Climate Services sections in Queensland, NSW, SA, Victoria and Tasmania at the following numbers:
THE NEXT ISSUE OF THE SEASONAL OUTLOOK IS EXPECTED BY 22nd September 2009