The NINO3.4 index is one of several El Niņo/Southern Oscillation (ENSO) indicators based on sea surface temperatures.
NINO3.4 is the average sea surface temperature anomaly in the region bounded by 5°N to 5°S, from 170°W to 120°W. This region has large variability on El Niņo time scales, and is close to the region where changes in local sea-surface temperature are important for shifting the large region of rainfall typically located in the far western Pacific.
An El Niņo or La Niņa event is identified if the 5-month running-average of the NINO3.4 index exceeds +0.4°C for El Niņo or -0.4°C for La Niņa for at least 6 consecutive months.
Flood-affected farmers in the Ravensthorpe shire on the south coast of WA say the State Government has been slow in reacting to their plight, adding there is a lack of comprehension around the scale of the damage.
The seasonal outlook for autumn is hot and dry, but what is causing it? Both maximum and minimum temperatures look to be above average, especially for central Australia, extending down through inland NSW and western VIC.
Wrapping up a hot and humid summer many will be happy to forget, rain is on its way for most of NSW east of the divide.