|Northern Aust Seasonal Rainfall Outlook: probabilities for November 2007 to January 2008, issued 25th October 2007|
Increased falls for parts of northern Australia
The northern Australian outlook for total rainfall over the early to mid-wet season (November to January), shows a moderate to strong shift in the odds favouring above average falls from the NT to southern Queensland and northern NSW.
The pattern of seasonal rainfall odds across northern Australia is mainly a result of continuing higher than average temperatures over parts of the tropical and sub-tropical Indian Ocean.
The chances of exceeding the median rainfall for the November to January period are between 60 and 70% in a broad region stretching over most of the NT and then across western and southern Queensland (see map). In parts of the northern and central NT the chances approach 75%.
So for every ten years with ocean patterns like the current, about six or seven November to January periods are expected to be wetter than average in these parts of northern Australia, while about three or four are drier.
Over northern Queensland the chances of exceeding the three-month median rainfall are between 45 and 60%.
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 most of Queensland and the NT (see background information).
A late-developing La Niña event is in progress across the Pacific Basin and computer models indicate it will persist at least until the early part of 2008. The 30-day value of the Southern Oscillation Index (SOI) was +1 as at 22nd October. 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 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 and the Northern Territory at the following numbers:
THE NEXT ISSUE OF THE SEASONAL OUTLOOK IS EXPECTED BY 27th NOVEMBER 2007