NSW Seasonal Rainfall Outlook: probabilities for April to June 2004, issued 17th March 2004

Mixed June quarter rainfall odds across NSW

The Bureau's seasonal rainfall outlook for the June quarter shows that a wetter than average season is more likely in northeast NSW and along parts of the central NSW coast. However, in the southwest of the State, a drier than average season is the more likely outcome.

For the April to June period, the chances of above median rainfall are between 30 and 40% across southwest NSW (see map). This means that BELOW median falls have a 60 to 70% chance of occurring in this part of the State, or in other words with climate patterns like the current, about 7 seasons out of 10 are expected to be drier than average in the southwest, with about 3 out of 10 being wetter. This part of the outlook is a result of above average temperatures in both the Pacific and Indian Oceans.

probability of exceeding median rainfall - click on the map for a larger version of the map

Conversely, the chances of above median falls are generally in the 60 to 65% range in the northeast quarter of NSW and along parts of the central NSW coast. So with climate patterns like the current, about 6 seasons out of 10 are expected to be wetter than average in these areas, with about 4 out of 10 being drier. This part of the outlook come mostly from the above average Indian Ocean temperatures.

Outlook confidence is related to the influence of Pacific and Indian Ocean temperatures on seasonal rainfall. During the June quarter, history shows this influence to be moderately consistent across both the southwest and northeast of NSW, that is, the areas with the large probability shifts (see background information).

Both the Indian and tropical Pacific Oceans remain warmer than average. For more detail see the the El Niño Wrap-Up.

The Southern Oscillation Index (SOI) has shown strong month-to-month variations recently, in association with active and inactive phases of the northern Australian monsoon. February's value was +9 following the –12 in January and +10 in December. The approximate SOI for the 30 days ending 14th March was +4.

 

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 (EDT) Monday to Friday by contacting the Climate and Consultancy section in the Bureau's Sydney Office: (02) 9296 1522.
 

THE NEXT ISSUE OF THE SEASONAL OUTLOOK IS EXPECTED BY 19th APRIL 2004.

Corresponding temperature outlook

February 2004 rainfall in historical perspective

December 2003 to February 2004 rainfall in historical perspective

 

Background Information