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.
Severe thunderstorms that ravaged the Hunter region and the Central Coast of New South Wales are over, the Bureau of Meteorology says, but Ausgrid and SES volunteers are still working to repair the damage.
More than 12,000 insurance claims have already been lodged with damages at an estimated $31 million following the .
Southern parts of the Gulf of Carpentaria have been lashed with heavy rain and gusty winds as a tropical low makes its presence felt.