Seasonal Climate Outlook Message for April to July 2003

The bottom line

SOI values remain low (dated 23/04/03)

The 30day average of the SOI continues to remain low and as of the 23rd April is minus 7.8.

Despite this low SOI value rainfall probabilities across Queensland are somewhat mixed. For the far north west and peninsular region along with pockets of the south east and south west of the state, the chance of getting above the long term April to June median rainfall remains low at around 20-40%.

For the rest of the state though, especially across parts of central Queensland, rainfall probabilities have lifted to around 50-70%.

Over the past few weeks some big rainfall events have been recorded around Queensland. It's worth noting though that these events have been patchy and there are still many areas that have had insufficient rainfall to run creeks and fill dams.

Pasture response to rainfall received earlier this year has been excellent in parts of central and southern Queensland. However, the response in the much of the western Mitchell grass regions has been limited and light falls have ruined the existing standing dry pasture stubble in some areas. Due to the late arrival of the summer rain season, the window for good pasture growth has generally been short resulting in minimal bulk or body. Therefore many producers are going into winter with pasture levels well below the desired level and are hoping for a good winter forage crop season to improve conditions. There are also expectations of large winter cereal crop plantings especially in those regions with substantial subsoil moisture.

Much interest will be shown in the next passage of the MJO. As regular readers of this column will be aware, 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.

However it can also help generate westerly wind bursts in the central Pacific, which at this time of year can be the trigger event for a 'regenerated' El Nino event.

The last passage of the MJO occurred in the first week of April and coincided with some widespread patchy storm and rain activity. If its' timing remains current it will next be due in mid May.