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 flood-hit area of Forbes in central-western NSW is readying itself for the worst of a slow-moving flood, with the peak expected to hit after midnight.
Farmers near Forbes in the New South Wales central west are bracing for extensive loses as their crops continue to be inundated with flood waters, which are expected to peak later today.
Southwestern parts of Western Australia have had rain of up to 24mm of rain this morning as another cold front swept over the region.