|Northern Aust Seasonal Rainfall Outlook: probabilities for Autumn 2008, issued 26th February 2008|
Wetter autumn favoured in northern Queensland
The northern Australian outlook for autumn rainfall (March to May), shows a wetter than normal season is favoured in northern Queensland.
The pattern of seasonal rainfall odds across northern Australia is a result of cooler than average waters across the equatorial Pacific in association with La Niña, and continuing higher than average temperatures in the central to southeastern Indian Ocean.
The chances of exceeding the median rainfall over March to May are between 60 and 70% over most of north Queensland, and generally close to neutral, between 55 and 60% elsewhere (see map). So for every ten years with ocean patterns like the current, about six or seven autumns are expected to be wetter than average in northern Queensland, while about three or four are drier. Elsewhere, the chances of being wetter than normal are about the same as the chances of being drier.
Outlook confidence is related to how consistently the Pacific and Indian Oceans affect northern Australian rainfall. During autumn, history shows this effect to be moderately consistent across much of the northern third of the country. In southern Queenland and the southern NT the effect is only weakly or very weakly consistent (see background information).
A La Niña event is in progress across the Pacific Basin and computer models indicate it is likely to persist until the end of autumn. The 30-day value of the Southern Oscillation Index (SOI) was +20 as at 23rd February. 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 28th March 2008