Seasonal Climate Outlook Message for January to April 2001

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SOI message 24th January 2001

The average SOI over the previous 30 days is now +7.8. Based on the SOI, the probabilities of exceeding median rainfall during the total period from January to March range mainly between 50 and 80% for much of Queensland including the Central Highlands, the central coast, and parts of the northern inland. Note that a positive SOI does not always mean high rainfall probabilities.

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Review of Climate Forecasts and Information. Date: 3rd January 2001. Climate pattern and SOI 'phase'. Our forecasts indicate the chances of useful rain through mid- summer for most regions in eastern Queensland are relatively high, especially the Central Highlands, central coast, and parts of the northern inland.

Probabilities of exceeding median rainfall are 60-80% in the Central Highlands and central coast of Queensland, southern coastal regions of NSW and the far north-west of NSW. Conversely, there is only a 20-40% chance of exceeding median rainfall in south- western Victoria and south-western Tasmania. Remaining areas of eastern Australia have a rainfall probability little different from the 'normal' for this time of year. Note that a 70% probability of receiving the long- term median for a location also means there is a 30% probability of not receiving the median for that location. These probability values are simply statements of fact referring to the history of rainfall events for particular locations over the past 100 years.

Sea-surface temperatures (SSTs). Since June we have primarily been in a "neutral" climate pattern. However over the past few months SSTs have cooled in some key regions of the eastern equatorial Pacific Ocean. This has created a pattern resembling a La Niña pattern; 1998 and 1999 were well-defined La Niña patterns.

Temperatures of waters off the coasts of eastern Qld and northern NSW are around average. However to the north of Australia in waters surrounding Indonesia, SSTs are much warmer than average.

Some general circulation models are suggesting the potential for warming in the eastern equatorial Pacific Ocean over the next 6-9 months. We will watch the situation closely to determine any potential for El Niño development, or otherwise, in 2001. Close monitoring of sea-surface temperature patterns over the next six months is suggested.

Pasture Growth forecasts. The probabilities of obtaining median pasture growth or better during the December-January-February period are 'above- average' over most of Qld. However there are regions in the southeast where the probabilities are only 10% to 30% due to poor soil moisture conditions.

30 to 50-Day Oscillation. The next passage of the 30 to 50-Day Oscillation over Qld is expected during the last week of January to the first week of February.

This message will next be updated in the first week of February.