ENSO Wrap-Up
Current state of the Pacific and Indian oceans


Weekly sea surface temperatures

Graphs of the table values

Monthly sea surface temperatures

Graphs of the table values

5-day sub-surface temperatures

Monthly temperatures

Southern Oscillation Index

30-day SOI values for the past two years
Select to see full-size map of 30-day Southern Oscillation Index values for the past two years, updated daily.

Trade winds

5-day SST and wind anomaly from TAO/TRITON
Select to see full-size map of 5-day SST and wind anomaly from TAO/TRITON.

Cloudiness near the Date Line

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ENSO outlooks

NINO3.4 SST plumes from POAMA forecasts, updated daily
Select to see full-size map of NINIO3.4 SST plumes from POAMA forecasts, updated daily.

Indian Ocean Dipole outlooks

IOD SST plumes from POAMA forecasts, updated daily
Select to see full-size map of IOD SST plumes from POAMA forecasts, updated daily.

For the week ending 13 August sea surface temperatures (SSTs) were close to average across most of the equatorial Pacific Ocean. Generally weak warm anomalies are present across much of the South Pacific, with stronger anomalies around much of the east coast and southeast Australia.

The NINO3.4 SST anomaly has continued to cool during the past fortnight, and is now at 0.0 °C. NINO3 has also cooled, to +0.1 °C, while NINO4 has warmed slightly during the past week and is now +0.4 °C.

The El Niño—Southern Oscillation (ENSO) is currently neutral. All international climate models surveyed by the Bureau suggest the tropical Pacific Ocean is likely to stay ENSO neutral for the remainder of 2017.

Sea surface temperatures (SSTs) have cooled over much of the central tropical Pacific during the past four weeks, and are now close to the long-term average, and within the neutral range. The 30-day Southern Oscillation Index (SOI) also remains neutral, having steadied over the past three weeks. Other indicators of ENSO, such as cloudiness near the Date Line and trade winds are also at neutral levels.

The Indian Ocean Dipole (IOD) also remains neutral with consensus amongst climate models suggesting neutral conditions are likely to persist. Some models suggest positive IOD thresholds could be reached in the coming months but these values are unlikely to be sustained long enough to classify as a positive IOD event. Positive IOD events are typically associated with below average winter and spring rainfall over central and southern Australia.

Cloudiness near the Date Line during the past two weeks has fluctuated around average values, as it has done for the past four months.

Equatorial cloudiness near the Date Line typically increases during El Niño (below average OLR) and decreases during La Niña (above average OLR).

Trade winds for the 5 days ending 13 August were slightly stronger than average over the western tropical Pacific and near average in the central and eastern tropical Pacific.

During La Niña events, there is a sustained strengthening of the trade winds across much of the tropical Pacific, while during El Niño events there is a sustained weakening, or even reversal, of the trade winds.

All eight of the international climate models surveyed by the Bureau indicate that ENSO-neutral conditions are likely to persist until at least the end of 2017.

SST anomalies for July show sea surface temperatures were slightly warmer than average along the equator in the Pacific Ocean. Weak warm anomalies are also located across most of the Pacific south of the equator, including around Australia, and across waters around southern and western Australia, to the north of the Maritime Continent, and large parts of the North Pacific between about 20 and 30°N.

The July values for the NINO3.4, NINO3 and NINO4 regions were +0.4 °C, +0.3 °C and +0.5 °C, respectively. NINO3.4 cooled slightly compared to June, while the other two held steady.

The 30-day Southern Oscillation Index (SOI) to 13 August is within the neutral range at +4.7 (90-day value +1.0), having steadied over the past three weeks.

Sustained positive values of the SOI above +7 typically indicate La Niña while sustained negative values below −7 typically indicate El Niño. Values between about +7 and −7 generally indicate neutral conditions.

The Indian Ocean Dipole (IOD) is neutral. The weekly index value to 13 August was +0.15 °C.

Most of the climate models surveyed by the Bureau indicate that the IOD will remain neutral during spring.

The four-month sequence of sub-surface temperature anomalies (to July) shows water temperatures in the sub-surface of the equatorial Pacific Ocean are generally close to average. Areas of weak warm anomalies persist in the top 150 m of the tropical Pacific west of 160°E, while an area of weak cool anomalies is present at around 150 m depth between the Date Line and 150°W.

The sub-surface temperature map for the 5 days ending 13 August shows temperatures are generally close to average across the equatorial Pacific Ocean.

Product code: IDCKGEWW00