The monthly value of the Southern Oscillation Index (SOI) was -19.1 in April and +2.8 in May. According to the SOI Phase system, the SOI is in a ‘Rapidly Rising’ phase.
A map showing the probability of above-median rainfall for the next three-month period (June to August) is available. This map is based on previous years from 1900 to 1998 which, like 2016, had a rapidly rising SOI over April and May (i.e. 1906, 1909, 1915, 1916, 1924, 1930, 1938, 1942, 1945, 1952, 1955, 1962, 1964, 1965, 1968, 1970, 1973, 1978, 1979, 1980, 1981, 1983, 1988, 1990, 1992 and 1998). This map indicates a 40 to 60 per cent probability of above-median June to August rainfall for most of Queensland, with higher probabilities for southern border regions.
When using a climate outlook it should be remembered that the probability, or per cent chance, of something occurring is just that – a probability. For example, if there is a 70 per cent probability of above-median rainfall, then there is also a 30 per cent chance of below-median rainfall. It does not mean that rainfall will be 70 per cent more than the median.
Furthermore, while climate outlook schemes cannot provide outlooks with absolute certainty, users who follow a skilful scheme should benefit from doing so in the long-term. Thus, users should consider the historical track record of any scheme, and such information is becoming increasingly available.
Further seasonal climate outlook information for Queensland is available in the Monthly Climate Statement produced by the Department of Science, Information Technology and Innovation.