Seasonal Climate Outlook Message for July to October 2004

The bottom line

Caution remains on longer-term outlook (21st July)

Since mid-June, the SOI has remained in negative values and as of the 21st July the 30day average is minus 11.1.

If this negative SOI pattern becomes firmly established over the next few weeks, it will create problems with the seasonal outlook later in the year. For example, a "Consistently Negative SOI Phase" at the end of this month will give a low (less than 30%) chance of getting above median rainfall for the following 3months across most of eastern Australia. This type of pattern is also usually associated with a later than average start to the spring/summer rainfall season for northern Australia.

In general broad terms, the current unusual fluctuations in the SOI (minus 16.2 at the end of April, plus 13.0 at the end of May, Minus 13.9 at the end of June) are somewhat similar to what happened at this time of year in 1946, 1957, 1965, 1986 and 1992. These years had a rather patchy rainfall pattern with many areas receiving below average to well below average rainfall.

This is why we continue to recommend a cautious approach when considering property management decisions and the longer-term outlook. Daily updates on the SOI are available on (07) 46881439.

I have had a number of requests for my "favourite" weather (as distinct from climate) internet sites. I have listed a few below with a brief description of them. Please note that I make no comment on the quality or accuracy of any of the information presented on these sites.

The Australian Bureau of Meteorology ->

This site is without a doubt a great source of information that I use regularly. This a comprehensive site containing daily and longer term forecasts for across Australia, the latest synoptic charts and maps, the latest radar and satellite images, historical records and long term averages on rainfall, temperature etc, weather warnings, hydrology and educational information etc. Well worth looking at regularly.

James Cook University Metsat ->

This site shows full colour satellite images from the Japanese GMS satellite. Updated daily and provides detailed images of current as well as recent weather events.

COLA - IGES short term outlooks ->

This site has temperature and rainfall modelled outlooks for a number of countries (including Australia) showing 0-5 and 6-10 day outlooks plus 10-day anomalies.

Fleet Numerical Meteorology and Oceanography Centre ->

This is a US Navy site that provides information on meteorology, oceanography and climatology. It also has links to the latest global satellite images and provides a 6day outlook for a number of countries and regions including Australia. To get to the 6day outlook click on the "Australia N.Z." tag on the right hand side of the page. The click on the "all" tag in the table beside the product label "Previous 12-hr Precipitation Rate [mm/12hr] and Sea Level Pressure [hPa]".

When incorporating climate (or weather or financial etc) forecasts into management decisions, it could be worthwhile to consider the following general rules of thumb developed from feedback from climate users.

The first point is to be sure of your source of information and what it is actually suggesting. Do not take a quick grab of information from any source including radio, TV or the internet and assume what you heard/saw/read applies to your location.

Management decisions should never be based entirely on one factor (such as a weather or climate forecast). As always, all factors that could impact of the outcome of a decision (such as soil type, moisture level, crop or pasture type/availability, commodity prices, machinery, work force, transport, finance, costs, seasonal outlook etc) should be considered.

It has also been shown to be useful to do a cost benefit analysis of any decision with a climate risk factor eg What will I gain if I get the desired outcome from this decision? What will I lose if I don't get the desired outcome from this decision? What other cost neutral options do I have, if any?

For more information contact us on 13 25 23.

Last updated: 20 July 2004