Seasonal Climate Outlook Message for April to July 2009

The bottom line

SST warming but still in neutral pattern Dave McRae, Qld Climate Change Centre of Excellence, 07/04/09

According to the latest ENSO wrap-up from the Bureau of Meteorology a neutral sea surface temperature (SST) and climate pattern can be found in the equatorial Pacific (key region running along the equator from the international dateline west towards South America).

SST's in this region though have warmed over the last couple of months. This is a trend away from the cooler La Nina like SST pattern that was a feature of the last 6 to 9 months.

It is also worth noting that a consistent and maintained warming of SST in this region throughout autumn and into winter would be viewed as a precursor for the development of an El Nino climate pattern. Therefore QCCCE staff will closely monitor what happens over the next few months especially as autumn is a key time for the establishment of climate phenomena such as El Nino and La Nina.

The majority of the surveyed global climate models are forecasting a neutral SST pattern through to at least July 2009. Interestingly none are forecasting any potential return of La Nina or La Nina like conditions.

For more information on SST's or climate patterns in the Pacific try or or

In the mean time the monthly values of the SOI fell from February (+15.2) to March (-1.5). Based on historical rainfall records and a Rapidly Falling SOI phase at the end of March, there is a lower 30 to 50% chance of getting above median rainfall during April through to the end of June across most of Queensland.

For those who like to follow the relationship between the SOI and rainfall patterns in more detail, have a look at what happened in your area during April to June in the following years since 1950 that have had a Rapidly Falling SOI phase at the end of March: 1951, 1955, 1961, 1966, 1968, 1977, 1979, 1980, 1981, 1984, 1985, 1991, 1994, 1997 and 2002.

Find out your average rainfall for April to June and see how many times rainfall was well below, well above or close to average during April to June in the listed years.

The 30day average of the SOI as of 6th April is plus 1.9. You can receive a text message with the latest SOI values sent to your mobile phone. To subscribe to this free service, call me on (07) 4688 1459.

Last updated: 6 April 2009