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

Following links open in new window

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.

Sea surface temperatures (SSTs) in the central tropical Pacific Ocean remain within neutral thresholds, but have cooled slightly in the eastern region during the past fortnight.

SSTs in the western Pacific remain warmer than average, with large areas of water around northern Australia and South East Asia more than 1 °C warmer than average for the week ending 17 July.

Warm SST anomalies in excess of 1 °C warmer than average also extend across much of the eastern Indian Ocean. Meanwhile, areas in the northwest of the Indian Ocean basin remain cooler than average, consistent with the classic pattern of a negative Indian Ocean Dipole (IOD) event.

 

 

 

ENSO indicators in the Pacific Ocean remain neutral, while sea surface temperatures in the Indian Ocean show a strong negative Indian Ocean Dipole (IOD).

Latest values of the IOD index show the dipole has strengthened in recent weeks. Climate models indicate the negative IOD will persist through to the end of spring. A negative IOD typically brings above average rainfall to southern Australia during winter-spring, with cooler daytime temperatures across southern Australia, and warmer daytime and night-time temperatures in northern Australia. Find out more about the Indian Ocean Dipole on our website.

In the tropical Pacific Ocean, recent model outlooks indicate a reduced chance of La Niña in 2016. Most climate models indicate the central Pacific Ocean will continue to cool, but only two of eight models show La Niña values through the southern spring. Recent observations of cloudiness, trade winds and the Southern Oscillation Index (SOI) show little change from normal patterns. These observations, combined with current climate model outlooks, means the Bureau's ENSO Outlook remains at La Niña WATCH. This means the likelihood of La Niña forming in 2016 remains a 50% chance.

Typically during La Niña, winter-spring rainfall is above average over northern, central and eastern Australia. If La Niña does develop, climate models indicate it will not be as strong as the most recent La Niña of 2010–12, which was one of the strongest La Niña on record.

Cloudiness near the Date Line has been close to average since the beginning of May, suggesting little change in coupling has occurred between the ocean and atmosphere.

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

Trade winds near the equator in the Pacific Ocean have remained close to normal for the 5 days ending 17 July, and since late June.

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.

While all models indicate more cooling in the tropical Pacific Ocean is likely, only five of the eight of the international climate models surveyed by the Bureau indicate that NINO3.4 values will pass below the La Niña threshold. However, model outlooks vary in how long this threshold is met, with only two of the eight models maintaining a La Niña outlook throughout the southern hemisphere spring.

If La Niña does form, models suggest it will be weak, and well below the strength of the significant 2010–12 event.

SSTs for June 2016 were warmer than average over parts of the tropical eastern and central Pacific away from the equator, with some of this area more than 1 °C warmer than average. Cool anomalies along the equator in the central Pacific have strengthened, when compared with May.

SSTs were more than 1 °C warmer than average over most of the region between Australia and Indonesia.

In the NINO3.4 region in the central Pacific, the June value was 0.0 °C, which was 0.4 °C cooler than for May and followed a drop during the previous month too. The values for the NINO3 and NINO4 regions, in the eastern and western Pacific respectively, remained similar to May.

SSTs in the western Indian Ocean cooled during June. SSTs in the central and eastern Indian Ocean also cooled but remain more than 1 °C warmer than average in some areas.

The latest 30-day Southern Oscillation Index (SOI) to 17 July 2016 is +1.8, which is well within the neutral ENSO range. The 30-day SOI has remained within the neutral range during the past month.

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) remains negative, with cool SST anomalies present in the northwest of the Indian Ocean and warm anomalies over the eastern and central parts of the basin. The index value to 17 July was −1.30 °C.

The Indian Ocean Dipole (IOD) index has been below the −0.4 °C negative IOD threshold for eight weeks. Last week’s index value, −1.37 °C, was the most negative value of the index in at least the past 15 years.

International climate models indicate the negative IOD will persist over the southern winter and spring.

A negative IOD typically brings above average rainfall to southern Australia during winter–spring, cooler than normal daytime temperatures to southern Australia, and warmer daytime and night-time temperatures to northern Australia.

The four-month sequence of sub-surface temperature anomalies (to June) shows cool anomalies span the entire width of the equatorial Pacific Ocean, although temperatures in top 50 m of water west of 160° W was mostly close to average in June. Cool anomalies have dominated all, or nearly all, of the equatorial sub-surface since during each month (March to June), but June has seen the spatial extent of the cool anomalies decrease compared to May.

The sub-surface temperature map for the 5 days ending 17 July shows temperatures remain slightly cooler than average across the top 200 m of the equatorial Pacific. However, compared to two weeks ago anomalies have lessened (i.e. temperatures have become closer to average) and temperatures in the top 50 m remain close to average.

A small area of water more than 3 °C cooler than average persists at around 140°W and 100 m depth.

Product code: IDCKGEWW00