|NSW Seasonal Rainfall Outlook: probabilities for April to June 2007, issued 26th March 2007|
Above-normal June quarter falls favoured in northeast NSW
The NSW outlook for total June quarter (April to June) rainfall, shows a moderate swing in the odds towards above-normal rainfall in the northeast quarter of the State. However, over most of NSW the chances of accumulating at least average rain for the coming three months are close to 50%.
The pattern of seasonal rainfall odds across New South Wales is mainly a result of recent higher than average temperatures in parts of the tropical and sub-tropical Indian Ocean.
The chances of exceeding the median rainfall for the April to June period are between 60 and 70% northeast of a line joining Jervis Bay, Nyngan and Cunnamulla (Qld) (see map). So in years with ocean patterns like the current, about six June quarters out of ten are wetter than average and four out of ten are drier in these regions with enhanced odds.
Outlook confidence is related to how consistently the Pacific and Indian Oceans affect Australian rainfall. During the June quarter, history shows this effect to be moderately consistent along the coast and ranges from Wollongong to the Queensland border, in the northern border regions around Walgett and in the far southwest of the State near the Victorian and SA borders. Elsewhere the effect is only weakly or very weakly consistent (see background information).
The Southern Oscillation Index (SOI) has been rising recently with values of −7 in January, −3 in February and an approximate 30-day value of +5 as at 21st March.
The 2006/07 El Niño has ended, with central to eastern Pacific temperatures having cooled to near-average. There is an increased chance of a La Niña developing in 2007 - for routine updates and comprehensive discussion on any developments in this regard 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 information on this outlook is available from 9.00am to 5.00pm (EST) Monday to Friday by contacting the NSW Climate Services section in the Bureau's Sydney Office: (02) 9296 1525.|
THE NEXT ISSUE OF THE SEASONAL OUTLOOK IS EXPECTED BY 23rd APRIL 2007