Marginal Improvement in Outlook Dave McRae, Qld Climate Change Centre of Excellence, 19/01/10.
Based on a "Near Zero" SOI phase and historical rainfall records, there is a 40 to 50% chance of getting median rainfall for January through to the end of March across most of Queensland. While the outlook is not as positive as many would like, there has been a marginal improvement in the seasonal outlook and as Queensland is in its summer rainfall season there remains a reasonable chance of getting some useful relief rain.
For those who like to follow the relationship between the SOI and rainfall patterns in more detail have a look at what happened in your area during January to March in the following years since 1970; 1970, 1972, 1975, 1979, 1980, 1981, 1982, 1984, 1985, 1986, 1988, 1990, 1991, 1993, 1994, 2006 and 2007. Work out your long term average or median rainfall for January to March and see how many times rainfall was well below, well above or close to average.
For example at Springsure, below average rainfall for January to March in those years was recorded 4 times, close to average rainfall was recorded 11 times with above average rainfall recorded twice. Therefore rainfall during January to March at Springsure is more likely to be close to average than well below or well above average. For more information refer to Rainman StreamFlow. The latest outlook maps are available at www.longpaddock.qld.gov.au
When using a climate forecast you should remember that the probability or percent chance of something occurring is just that - a probability. For example if there is a 70% chance of recording more than 100 mm there is also a 30% chance of recording less than 100 mm i.e. 70-30; 30-70. It does not mean that you will get 70% more than 100 mm or 100 mm plus another 70%.
When I'm asked about how climate information can be used I refer to a couple of key points developed from client feedback. Key points include that management decisions should never be based entirely on one factor such as a climate or weather forecast. As always, everything that could impact of the outcome of a decision (soil moisture, pasture type/availability, crop and commodity prices, machinery, finance, costs etc) should be considered. For example, the level of soil moisture at planting is the major factor influencing crop yield or success.
If anyone is interested I'm happy to give climate presentations at meetings or field days etc. For more information call me on (07) 4688 1459 or e-mail email@example.com