SST Pattern Interesting Dave McRae Qld Dept of Primary Industries and Fisheries 12/11/05
The current sea surface temperature anomaly map is interesting due to the area of warmer than normal sea surface temperatures (shown by red/yellow colours) that can be found around Australia's eastern and northern coastline. If sea temperatures in this region continue to warm it should have a positive influence on our expected late spring/summer rainfall.
According to the latest "El Niño wrap up" from the Bureau of Meteorology at www.bom.gov.au/ the key climate indicators confirm the continuation of a neutral sea surface temperature pattern in the central Pacific Ocean. It is unlikely that this pattern would change in the short term with a negligible chance of either an El Nino or La Nina developing. For more information on conditions in the Pacific try the US Climate Prediction Centre at www.cpc.ncep.noaa.gov/
The last active phase of the MJO in mid-October helped trigger some welcome falls of rain. The timing of MJO events has been reasonably consistent since May averaging around 45 days. If this timing remains the same the next active phase should begin across northern Australia in early December.
The MJO is a band of low air pressure originating off the east coast of central Africa travelling eastward across the Indian Ocean and northern Australia roughly every 30 to 60 days. Research has shown the MJO to be a useful indicator of the timing of potential rainfall events (but not amounts). For more information try www.apsru.gov.au/mjo/
It is the changes in Pacific Ocean sea surface temperature (SST) patterns running along the equator from the west coast of South America to around the International Dateline that drive the changes in the atmosphere that influence our local climate.
The SOI is a useful way of measuring these changes and is simply the difference in barometric air pressure between Darwin and Tahiti. It ranges in value from plus 30 to minus 30. While measured on a daily basis, it is the shift in monthly value of the SOI (Consistently Positive, Negative, Rising, Falling, Near Zero) that is used to indicate for example, whether the coming three months is likely to be wetter or drier than normal. This relationship can also be used to investigate the chance of extreme climate events.
The latest rainfall probability maps are at www.dpi.qld.gov.au/climate or www.longpaddock.qld.gov.au and daily updates on the SOI are available on (07) 46881439. For more information contact the DPI&F Call Centre on 13 25 23.