|Qld Seasonal Rainfall Outlook: probabilities for January to March 2007, issued 20th December 2006|
Decreased rainfall in March quarter for much of Queensland
The latest seasonal rainfall outlook issued by the Bureau of Meteorology shows a moderate shift in the odds towards below-normal March quarter (January to March) rainfall for much of Queensland and northern NSW. However, the confidence in the outlooks at this time of year is rather low, so this outlook should be used with caution.
The pattern of seasonal rainfall odds across Queensland is mostly a result of higher than average temperatures in the Pacific Ocean (because of El Niño).
The chances of exceeding the median rainfall for the January to March period, are between 30 and 40% in Queensland east of a line from Wanaaring (NSW) to Cloncurry to Townsville. This means that BELOW median falls have about a 60 to 70% chance of occurring. So in years with ocean patterns like the current, about six or seven March quarters out of ten are expected to be drier than average over much of Queensland, with about three or four out of ten being wetter.
Outlook confidence is related to how consistently the Pacific and Indian Oceans affect Australian rainfall. During the March quarter, history shows the effect to be moderately consistent through eastern parts of Queensland, but only weakly or very weakly consistent elsewhere in the State (see background information).
The Southern Oscillation Index (SOI), negative for the seventh straight month as a result of the El Niño, rose from −15 in October to −1 in November. The approximate SOI for the 30 days ending 17th December was −4.
The current Pacific El Niño pattern, of which the low SOI is but one indicator, is expected to persist for most of the summer. 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.