AN EL Niño pattern is still present in the Pacific Ocean. As well as the warmer than normal surface and subsurface sea temperatures (+1 -3°C) throughout the central Pacific, westerly wind bursts (rather than 'normal' south-east trade winds) continue to persist along the equator near the international dateline.
Given current dry conditions across most of Australia (as Ground Cover went to press in January), atmospheric/oceanic developments over the next few months will be crucial — autumn is the usual transition period for these events.
Based on previous El Niño events as well as information sourced from the US Climate Prediction Centre, it is very likely that the current El Niño event will linger through to mid/late autumn at least.
El Niño change: not a direct prediction of drought's end
It is worth pointing out that this is not a prediction of when the drought is going to break. That may take several months of continual above-average falls in some regions and often, unfortunately, the breakdown does not occur evenly across all drought-affected areas.
For more information on the longer-range ocean and coupled ocean/atmosphere (ENSO) forecasts, try www.bom.gov.au/climate/ahead.
The monthly value of the SOI for November was minus 4. 1 and for December was minus 13. 4. Based on these monthly values the SOI is in a 'Rapidly Falling' phase.
Other years that have had the same SOI phase in December include 1908, 1912, 1918, 1934, 1935, 1940, 1943, 1948, 1952, 1972, 1976, 1991, 1995 and 2001.
What were rainfall patterns and farming conditions like for January-March in your area following those years?
Case studies for management decisions
Many producers and industry groups are interested in how climate forecasts can be used in management decisions. Some interesting case studies developed by the Climate Variability in Agriculture Program (CVAP) can be found at www.cvap.gov.au/mastersoftheclimate/
They highlight how some producers have used climate information in their management decisions and are well worth reading.
Many producers have also found it beneficial to do a cost-benefit analysis of any decisions with a climate risk factor. For example, what will I gain if I get the desired outcome from this decision? What will I lose if I do not get the desired outcome from this decision? What other options do I have?
As part of the QCCA science program, an experimental climate forecast system has been developed based on the pattern of tidal forces exerted by the sun and moon. Analysis suggests that tidally derived cycles may contribute to climate features like the Southern Oscillation Index and Pacific equatorial SSTs. Since the pattern of tidal force is predictable for centuries to come, any such connection would have obvious significant effects on our ability to forecast climate patterns. For more information try www.dpi.qld.gov.au/climate/9470.html.
For more specific rainfall data for your location, refer to Australian Rainman or contact me on 07 4688 1459. The latest seasonal outlook maps are also available on the DPI climate page www.dpi.qld.gov.au/climate or on www.longpaddock.qld.gov.au.