|Vic Seasonal Rainfall Outlook: probabilities for February to April 2007, issued 23rd January 2007|
Increased late summer to mid-autumn rains in western Victoria
The outlook for total February to April rainfall, shows a moderate shift in the odds towards above average falls in western Victoria and also along parts of the central coast. The pattern of seasonal rainfall odds across Victoria is mainly a result of higher than average temperatures in the Pacific Ocean (because of El Niño).
The chances of exceeding the median rainfall for the February to April period, are between 60 and 65% over the western quarter of Victoria and also extending along a narrow coastal strip towards Wilsons Promontory (see map). So in years with ocean patterns like the current, about six February to April periods out of ten are expected to be wetter than average in these parts of the State, with about four out of ten being drier. However, the outlook system has low skill at this time of the year, so this outlook should be used with caution.
Outlook confidence is related to how consistently the Pacific and Indian Oceans affect Australian rainfall. During the February to April period, history shows the effect to be mostly weakly consistent over Victoria (see background information).
December was the second successive month when the Southern Oscillation Index (SOI) was only slightly negative, with a monthly value of −3 following the −1 in November. A link to 30-day SOI values is available in the ENSO Wrap-Up (see next paragraph).
The neutral SOI is one of a few indicators which show that the current Pacific El Niño pattern is beginning to weaken. 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 Victorian Regional Office: (03) 9669 4949.|
THE NEXT ISSUE OF THE SEASONAL OUTLOOK IS EXPECTED BY 22nd FEBRUARY 2007