|Tas Seasonal Rainfall Outlook: probabilities for Autumn 2007, issued 22nd February 2007|
Neutral autumn rainfall outlook for Tasmania
The Tasmanian outlook for total autumn (March to May) rainfall, shows no strong swings in the odds towards wetter or drier conditions. The pattern of seasonal rainfall odds across Australia is a result of higher than average temperatures in the Pacific Ocean (because of El Niño) and also in the Indian Ocean. More influence has come from the Pacific.
The chances of exceeding the median rainfall for the March to May period, are close to 50% over Tasmania (see map). So in years with ocean patterns like the current, about five autumns out of ten are drier than average and five out of ten are wetter across the State.
Outlook confidence is related to how consistently the Pacific and Indian Oceans affect Australian rainfall. During autumn, history shows this effect to be only weakly or very weakly consistent across most of Tasmania (see background information).
The January Southern Oscillation Index (SOI) value was −7, a slight drop from the December reading of −3. The approximate SOI for the 30-days ending 19th February was −3.
The 2006/07 El Niño has ended. All the main ENSO indicators show that neutral conditions have returned to the Pacific Basin. 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.
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 Climate and Consultancy section in the Bureau's Hobart Office: (03) 6221 2043.|
THE NEXT ISSUE OF THE SEASONAL OUTLOOK IS EXPECTED BY 26th MARCH 2007