Climate monitor
Climate feature: Current sea-surface temperatures show a La Niña pattern more →
By the end of April 2008, as detailed in the outlook, sea-surface temperature anomalies show a weakening La Niña pattern...
This section of the website provides an overview of recent temperature and rainfall throughout the state, together with model calculations based on this data (e.g. soil moisture) of a range of parameters, and also a seasonal climate outlook based on the El Niño-Southern Oscillation phenomenon.
Seasonal conditions as at 1 May 2008
With the exception of parts of south-eastern and far-western Queensland, much of the State has received above-average rainfall over the last twelve months. The Southern Oscillation Index (SOI) has fallen from high very values over summer but still remains positive (+4.5 in April). Sea-surface temperatures show a weakening La Niña pattern as discussed in our climate feature last month.
Overview
See the following maps for three- and twelve-month summaries of seasonal conditions and modelled parameters.
- Minimum temperature
- Maximum temperature
- Rainfall
- Modelled soil moisture
- Modelled run-off
- Modelled groundcover
The top map in each pair shows conditions averaged over the most recent three-month season.
The lower maps give a long-term perspective, showing conditions averaged over the last twelve months.
Currently, it is of particular note that:
- For most of Queensland, minimum and maximum temperatures have been cooler than the long-term (1961-2008) average over the last three months.
- Three-month rainfall to the end of April has been well-above average only in coastal regions of northern Queensland.
- Twelve month rainfall to the end of April has been well-above average over much of inland Queensland, parts of southern Queensland and coastal districts in the far-north.
Effects of the global climate
Queensland’s climate is highly variable, both from year-to-year and from one decade to the next. Much of this variability is associated with fluctuations in the Southern Oscillation—a major ‘see-saw’ of air pressure and rainfall patterns between the Australian/Indonesian region and the south-eastern Pacific. Marked fluctuations in sea-surface temperatures and trade winds across the Pacific, particularly towards the equator, are associated with the Southern Oscillation. These atmospheric and oceanic fluctuations are closely linked. In fact, the ocean and atmosphere reinforce one another leading to what is known as the global ‘El Niño-Southern Oscillation’ (ENSO) phenomenon.
Southern Oscillation Index
The Southern Oscillation, which is monitored using a simple index known as the Southern Oscillation Index (SOI), tends to lock-in and persist in one mode (positive, neutral or negative) from winter through to the following summer each year. Negative or positive modes of the Southern-Oscillation (known respectively as El Niño or La Niña ‘events’) tend to form in late autumn or winter and then break down in late summer or early autumn. Climatologists also closely monitor sea-surface temperatures, sub-surface ocean temperatures, trade wind strength, location of convective activity and other factors associated with the El Niño-Southern Oscillation phenomenon in the equatorial Pacific.
Monthly Southern Oscillation Index (SOI) values with 90-day moving average
Outlook
All atmospheric and oceanic indicators now show a weakening La Niña pattern with further weakening of this pattern evident since last month. The La Niña pattern contributed to enhanced rainfall in eastern Australia in general, and Queensland in particular, since November 2007. At this time of year, there is a tendency for La Niña events (and the opposite “El Niño” events) to break down as is currently being witnessed. For this reason, the current positive SOI values are not a particularly useful guide to rainfall probabilities over coming months and particularly not into next summer. The QCCCE will monitor the Southern Oscillation Index and sea-surface temperature patterns through winter and spring to assess rainfall probabilities for spring and summer respectively.
Last updated 3 June 2008.