|WA Seasonal Rainfall Outlook: probabilities for August to October 2003, issued 16th July 2003|
WA rainfall odds mostly neutral for late winter/mid-spring
The Bureau's latest seasonal rainfall outlook shows near 50:50 chances across most of the country with no big swing towards wetter or drier conditions for the late winter to mid-spring period.
For the August to October period in Western Australia, the chances of above median rainfall are between 40 and 60%, apart from a small region near Meekatharra where they're below 40% (see map). So with climate patterns like the current, about 5 seasons out of 10 are expected to be wetter than average across the vast majority of the State, with about 5 out of 10 being drier.
It should also be noted that the August to October period is in the heart of the dry season across north and northwest WA and heavy rain at that time of year is uncommon.
The Outlook probabilities are based on recent Indian and Pacific Ocean temperatures. The tropical Indian Ocean is warmer than average, whilst the Pacific is showing a mixed pattern of warmer and cooler than average. For more detail see the El Niño Wrap-Up. The excess warmth in the Indian Ocean has had the greater influence on the overall pattern of probabilities.
June's value of the Southern Oscillation Index (SOI) was 12, five points below the May value of 7. The approximate SOI for the 30 days ending 13th July was 3.
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 (WST) Monday to Friday by contacting the Climate and Consultancy section in the Bureau's Perth Office: (08) 9263 2222.|
THE NEXT ISSUE OF THE SEASONAL OUTLOOK IS EXPECTED BY 19th AUGUST 2003.