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.
The 2016 snow season has reached a new peak depth this week according to measurements taken today.
Rain gauges as far north as the Gulf of Carpentaria and south to Ulladulla have received decent rainfall in the last 24 hours, some of which caused dangerous flooding.
A friend of a man feared drowned in floodwaters near Kyogle has told of "helplessly watching" the 72-year-old as he clung to a tree before being swept downstream.