|SA Seasonal Rainfall Outlook: probabilities for February to April 2007, issued 23rd January 2007|
Increased likelihood of late summer to mid-autumn rains in southern SA
The outlook for total February to April rainfall, shows a moderate shift in the odds towards above average falls in a broad band extending from central to southeast South Australia. The pattern of seasonal rainfall odds across SA is mostly a result of higher than average temperatures in the Pacific Ocean (because of El Niño).
The chances of exceeding the median rainfall for the February to April period, are between 60 and 65% south of a line from Ceduna to Woomera to Mildura. So in years with ocean patterns like the current, about six out of ten February to April periods are wetter than average and four out of ten are drier in this area with elevated odds.
Outlook confidence is related to how consistently the Pacific and Indian Oceans affect Australian rainfall. During the February to April period, history shows the effect to be moderately consistent in the far west of SA and a small part of the southeast, but over most of the State the effect is only very weakly consistent (see background information).
December was the second successive month when the Southern Oscillation Index (SOI) was only slightly negative, with a monthly value of −3 following the −1 in November. A link to 30-day SOI values is available in the ENSO Wrap-Up (see next paragraph).
The neutral SOI is one of a few indicators which show that the current Pacific El Niño pattern is beginning to weaken. For routine updates and comprehensive discussion on the latest data relating to El Niño, together with details on what the phenomenon is and how it has affected Australia in the past, please see the ENSO Wrap-Up.
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|More information on this outlook is available from 9.00am to 5.00pm (CST) Monday to Friday by contacting the Climate and Consultancy section in the Bureau's Adelaide Office: (08) 8366 2664.|
THE NEXT ISSUE OF THE SEASONAL OUTLOOK IS EXPECTED BY 22nd FEBRUARY 2007