SOI Worth Watching Over Next Few Months. Dated 20/02/02
Based on the recent pattern of the SOI, the probability of above median rainfall for February to April remains relatively positive (50-70%) in Queensland for the strip running from north west corner of the state to the Charleville district.
However, despite the recent rise in SOI values, rainfall probabilities for February to April remain low (30-40%) for the far south west and a large section of the eastern half of the state. This area includes much of the north, central, south and south east of the state.
The 30 day average of the Southern Oscillation Index (SOI) has continued to rise slowly and as of the 20th February is +8.1.
The last 30-50 day oscillation slowed considerably over January with its influence only becoming apparent in the first and second week of February. Its passage was marked by heavy rainfall events across parts of northern and central Australia as well as cyclone development in the Pacific and Indian oceans. It is next expected around late March. It is important to remember that while it is a tropical phenomenon it also appears to influence the potential timing of possible rainfall events across central and southern Queensland (rather than the actual amount of rain).
There is evidence that the impetus for the onset of an El Niño is strengthening. However more definitive information may not be available to later in autumn due to the variability that exists in sea surface temperature patterns over the next few months. Our strong advice is to continue to closely monitor information on SOI trends over the next few months.
Update for the March/April/May period on 6/03/02.