Seasonal Climate Outlook Message for April to July 2003

The bottom line

MJO due mid-May (Dated 09/04/04)

Much interest has been shown in the intra-seasonal oscillation (or MJO) over the past year as an indicator as to the timing of potential rainfall.

The MJO is simply a band of low atmospheric pressure originating off the east coast of central Africa travelling eastward across the Indian Ocean and northern Australia roughly every 30 to 50 days. While it is a tropical phenomenon, it appears to indicate the timing of potential rainfall events (but not indicate rainfall amounts) over central and southern Queensland.

It should also be remembered that while promising, the use of the MJO as a reliable forecast tool is still at the research/experimental stage. The last passage of the MJO has only just occurred (early April) and triggered some widespread but very patchy storm and rain activity. If its' timing remains current it will next be due in mid May and will hopefully bring some relief rain to those areas that have largely missed out.

It will also be interesting to see if it generates any strong westerly wind bursts in the central Pacific as these can be the trigger event needed to regenerate an El Nino at this time of year.

The 30day average of the SOI has fallen since the end of March and as of the 9th April is minus 10.4.

Last updated: 8 April 2003