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.
Parts of Victoria, Tasmania and South Australia could be lashed by storms and damaging winds on Thursday as a cold front sweeps across Australia's southeast.
It is storm season in Australia and, while being struck by lightning is considered a rare occurrence, there are several steps people can take to keep safe.
Storm-weary parts of southeast Queensland and northeast New South Wales are preparing for another bout of wild weather today.