Currently there is a period of La Niña (a coupled ocean-atmosphere phenomenon oposite to El Niño) which means the sea surface temperature across the equatorial Eastern Central Pacific Ocean will be lower than normal by 0.5 °C. This basically means that Australia will be wetter (more rain) during a period of El Niña. La Niña is often preceded by a strong El Niño, the latter being famous due to its potentially catastrophic impact on the weather along both the Chilean and Australian coasts. According to the model outlooks for El Niño and La Niña the La NiÃ±a has weakened which may be good news for all Aussies: good weather is coming! (but so may the draught :S)
Normal Pacific pattern. Equatorial winds gather warm water pool toward west. Cold water upwells along South American coast (the North East Australian cost is visible in the lower left corner of the map above).