|Tas Seasonal Rainfall Outlook: probabilities for November 2006 to January 2007, issued 26th October 2006|
50:50 chances for above average seasonal rainfall in Tasmania
The latest seasonal rainfall outlook for Tasmania issued by the Bureau of Meteorology, shows a neutral pattern of odds for exceeding the median rainfall over the late spring to mid-summer period (November-January).
The pattern of seasonal rainfall odds across Australia is a result of higher than average temperatures in both the Pacific and Indian Oceans. The warm Pacific biases the climate towards drier than average across eastern and northern Australia, but the warm Indian Ocean promotes wetter than average conditions across the tropics and in western WA.
The chances of exceeding the median rainfall for the November to January period, are generally very close to 50% over Tasmania. So in years with ocean patterns like the current, about five November to January periods out of ten are expected to be drier than average across the State, with about five out of ten being wetter.
Outlook confidence is related to how consistently the Pacific and Indian Oceans affect Australian rainfall. During the November to January period, history shows this effect to be moderately consistent across much of Tasmania (see background information).
The Southern Oscillation Index (SOI), negative for the fifth straight month, rose from −16 in August to −5 in September. The approximate SOI for the 30 days ending 23rd October was −14.
The current El Niño conditions, of which the low SOI is but one indicator, are very likely to persist for the rest of 2006, which would qualify it as an official El Niño event. 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 (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 23rd NOVEMBER 2006