Seasonal Climate Outlook Message for July to October 2005
The full story
SOI in Rising Phase 05/07/05
The monthly value of the SOI rose from minus 11.7 for May to plus 0.5 for June placing the SOI in a 'Rapidly Rising' phase. With the rise in value of the SOI most of the state has above a 60% chance of getting median rainfall for July through to the end of September.
For example at Miles there is a 70% chance of getting above 80 mm for July through to the end of September, Emerald has a 70% chance of getting above 55 mm, Roma has a 65% chance of getting above 75 mm, and Gympie has a 60% chance of getting above 115 mm.
It will be very interesting to see if the recent upward trend of the SOI is maintained over coming weeks or if it is just a short-term fluctuation. Daily updates on the SOI are available on (07) 46881439. The latest rainfall probability maps are at www.dpi.qld.gov.au/climate or www.longpaddock.qld.gov.au
It is also worth noting that the current outlook does not mean there will be excessive rainfall or floods for all of July to September for those areas with the higher rainfall probabilities. What it does means though, is that rainfall recorded in the affected areas will, more likely than not, be above median for this time of year.
Lower probabilities (less than 40 to 50%) of above median rainfall for July to September however can be found in western Tasmania, much of Western Australia and for north-eastern parts of the Northern Territory. For the rest of Australia there is generally above a 50 to 60% chance of getting above median rainfall for July to September.
Because rainfall probabilities and median rainfall levels vary between regions, we recommend referring to Rainman StreamFlow for more specific information. Otherwise call the DPI Call Centre on 13 25 23 or (07) 3404 6999.
Currently the MJO has low amplitude and is somewhat hard to discern. This is due to strong monsoon activity over India, SE Asia and convection over the South China Sea. Satellite imagery indicates the MJO is currently over Andaman Sea which means it should have an influence on our region late next week (week starting 11/07).
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) across much of Queensland. For more information on the MJO including its location try www.apsru.gov.au/mjo/ or try www.bom.gov.au/climate/tropnote/tropnote.shtml
Many people like to follow the relationship between the SOI and rainfall patterns in more detail. To do that, have a look at what happened in your area over July to September in the following years; 2001, 1998, 1996, 1986, 1973, 1970, 1967, 1966, 1958, 1957, 1953, 1951, 1950, 1947 and 1945 and compare the rainfall recorded with your 'normal' rainfall for July to September.
Information on what rainfall patterns where like for July to September in those years can be found at www.longpaddock.qld.gov.au or in Australian Rainman.
There has been a marked improvement in the latest wheat yield outlook especially for NSW and Queensland. This improvement was largely caused by above average rainfall during June improving soil moisture levels as well as the improvement in rainfall probabilities for July to September.
The APSRU/DPI&F wheat yield outlook is based on a shire scale. It does not take into account crop area planted and is purely a yield forecast. It does not take into account individual property circumstances or the effects and damage from poor crop nutrition, pests, diseases, frosts and distribution of planting rain within a shire. It should be noted that forecast quality of the crop outlook improves as the season progresses. For more information on the regional wheat crop outlook contact Andries Potgieter on (07) 46881417 or try www.dpi.qld.gov.au/climate where a full copy the wheat crop outlook can be found.
According to information from the Bureau of Meteorology "El Niño wrap up" at www.bom.gov.au/ key indicators in the Pacific suggest that the likelihood of a classic El Niño event developing this year has continued to recede. If this trend continues, the risk of a classic El Niño event developing this year will be substantially reduced.
The key region to watch for the development of El Niño or La Niña events runs east along the equator from the international dateline to South America. If sea surface temperatures (SST) in this region remain warmer than normal it is often associated with below median rainfall for much of eastern Australia.
The reason for the concern about the potential for an El Niño or borderline El Niño to develop this year has been that SST in the central equatorial Pacific have remained slightly warmer than normal. This is somewhat similar to the SST pattern that could be found for much of the second half of 2004 and early 2005. Rainfall for this period was below average for most of eastern Australia.
In terms of output from 12 surveyed reputable ocean or coupled ocean/atmosphere forecast models, 10 are showing a neutral SST pattern through to November with 1 showing an El Niño SST pattern and 1 showing a La Niña pattern. For more information on conditions in the Pacific try the IRI for Climate Prediction at http://iri.ldeo.columbia.edu/ or the US Climate Prediction Centre at www.cpc.ncep.noaa.gov/ Try www.longpaddock.qld.gov.au/
Despite the rain the number of drought declared shires in Queensland has increased. As of the 5th July there were 62 shires and 6 part shires drought declared under State government drought processes. This is approximately 60.6% of the land area of the State. There are also 107 Individually Droughted Properties (IDPs) in a further 17 shires.
The Queensland Government currently provides assistance to primary producers affected by severe drought. Information regarding drought declarations can be obtained from your local DPI Stock Inspector or the Rural Risk Strategies Unit. The unit can be contacted through the DPI&F Call Centre on 132523 or on (07) 3239 3181. For a full list of drought declared shires and the latest seasonal conditions report go to www.longpaddock.qld.gov.au/
As with any probability based forecast system it is important to consider the opposite aspect. For example, Nanango has a 75% chance of getting above 100 mm for July through to the end of September. This also means that there is a 25% chance of NOT getting 100 mm over July to September.
Another way of looking at this is that in around seven to eight years out of ten historically (or around three quarters) with the current SOI pattern, Nanango has received at least 100 mm over July to September. Therefore in two to three years out of ten historically (or around one quarter), Nanango has gotten less than 100 mm over July to September.
When looking at rainfall probabilities for your area it may make it easier to think of them in these terms:
1. Probabilities above 80% highlight a high chance 2. Probabilities above 60% highlight an above average chance 3. Probabilities below 40% highlight a below average chance 4. Probabilities below 20% have a low chance
