Seasonal Climate Outlook Message for May to August 2006

The bottom line

Climate Watch Dave McRae 30/05/06 Falling SOI Phase Gives Mixed Outlook for June to August Over the last few weeks the 30 day average of the SOI has had a pronounced downward trend from plus 13.0 at the end of April to minus 6.3 as of the 29th May. Based on this shift in value the SOI is now in a "Rapidly Falling" phase giving a mixed seasonal outlook throughout Queensland for June to August. For much of the southern third of the state as well as along the coastal strip there is a 20 to 40% chance of getting above median rainfall for June to August. Generally for the rest of the state the chance of getting above the long term June to August median rainfall is between 40 to 60%. If the SOI however where to remain in consistently negative values through to the end of June the chance of getting above median rainfall would reduce further. Current rainfall probability maps are at www.dpi.qld.gov.au/climate or www.longpaddock.qld.gov.au and SOI updates are available on (07) 46881439. As with any probability based forecast system it is important to consider the opposite aspect. For example, Roma has a 40% chance of getting its June to August median rainfall of 85 mm. This also means that there is a 60% chance of NOT getting at least its June to August median rainfall of 85 mm. Another way of looking at this is that in around 6 times out of 10 with the current SOI pattern, Roma has received less than 85 mm during June to August. Therefore around 4 times out of 10 with the current SOI pattern, Roma has received more than 85 mm over June to August. A Falling SOI phase at this time of year also increases the chance of getting below median minimum temperatures for June to August across much of Queensland. For more on rainfall probabilities, monthly averages or medians for your location refer to Rainman StreamFlow or contact the DPI&F on 132523.