The NINO3.4 index is one of several El Niño/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 Niño 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 Niño or La Niña event is identified if the 5-month running-average of the NINO3.4 index exceeds +0.4°C for El Niño or -0.4°C for La Niña for at least 6 consecutive months.
Tropical Cyclone Debbie has intensified to category four and is expected to hit the north Queensland coast on Tuesday morning, the Bureau of Meteorology (BOM) has warned.
After spending three days brewing over the Coral Sea, Severe Tropical Cyclone Debbie will make landfall tomorrow.
Evacuation centres are designed to be a safe place to wait out a cyclone â?? not be a home away from home.