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

Indian Ocean Dipole outlooks

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

Sea surface temperatures (SSTs) for the week ending 9 June remain warmer than average across almost all of equatorial Pacific Ocean. Most of the equatorial Pacific region is half to one degree warmer than average.

Waters are also warmer than average across much of the southwest Pacific, but the past fortnight has seen some cooling across this region. Sea surface temperatures around Australia are broadly close to average, with weak negative anomalies along parts of the western, northern and southern coastline, and weak positive anomalies along the eastern coastline.

The latest values of the three key NINO indices in the tropical Pacific for the week ending 9 June are: NINO3 +0.6 °C, NINO3.4 +0.8 °C and NINO4 +0.8 °C.

Persistent NINO3 or NINO3.4 values warmer than +0.8 °C are typical of El Niño, while persistent values cooler than −0.8 °C typically indicate La Niña.

The tropical Pacific Ocean and atmosphere remain near El Niño thresholds, meaning the ENSO Outlook remains at El Niño WATCH. Climate models suggest a gradual shift away from El Niño levels over the coming months. Indian Ocean temperature forecasts, on the other hand, show a positive Indian Ocean Dipole (IOD) through the southern winter, which is likely to be the dominant climate driver for Australia.

A fortnight ago, a pulse of the Madden–Julian Oscillation (MJO) weakened trade winds, which led to some renewed warming at the surface of the tropical Pacific Ocean. However, this MJO pulse has passed, returning trade winds to normal levels. With little warmth in the ocean sub-surface, most climate models suggest the tropical Pacific will cool, shifting away from El Niño thresholds, during winter.

In the Indian Ocean, waters off Sumatra have cooled over the past fortnight, with the IOD index now exceeding positive thresholds for three weeks. All but one of the climate models suggest positive IOD values will persist through winter and into spring. To be considered a positive IOD event, positive thresholds need to be maintained for at least two months. Typically, a positive IOD brings below average winter-spring rainfall for southern and central Australia. This is currently being reflected in the rainfall outlook for the coming months.

Cloudiness near the Date Line has been generally above average since early December, however, since late April values have been closer to average.

Equatorial cloudiness near the Date Line typically increases during El Niño (negative OLR anomalies) and decreases during La Niña (positive OLR anomalies).

Trade winds for the 5 days ending 9 June were close to average across the tropical Pacific.

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

Most climate models forecast the tropical Pacific Ocean to cool over winter and into early spring.

While four of the eight surveyed climate models anticipate El Niño thresholds will be met for July, by August all models are in ENSO neutral territory. However, October and November see two models rebound back to El Niño levels, with the remaining six models continuing neutral conditions.

SSTs for May were warmer than average across most of the tropical Pacific Ocean. Temperature anomalies in some areas decreased slightly from April.

SSTs show a broad area of warmer than average water surrounds southeast Australia, extending across the Tasman Sea and well to the east of New Zealand; temperatures are up to two degrees warmer than average in much of this region. Much of the rest of the Australian region SSTs are close to normal, but weak negative anomalies are present to the southwest of Australia.

The May values for NINO3 were +0.7 °C, NINO3.4 +0.7 °C, and NINO4 +0.6 °C, with values holding steady compared to April.

The 30-day Southern Oscillation Index (SOI) has seen recent values fall to El Niño levels, but in the longer-term, values remain neutral. The SOI for the 30 days ending 9 June is −9.6, with the 90-day average −6.2.

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

The Indian Ocean Dipole (IOD) index has been positive for the past three weeks. The latest weekly index value to 9 June is +0.67 °C.

Five of the six international climate models surveyed by the Bureau indicate positive IOD values are likely to continue through the austral winter and spring, suggesting the Indian Ocean may currently be in the early stages of a positive IOD event.

A positive IOD often results in below average winter–spring rainfall over southern and central Australia.

The four-month sequence of equatorial sub-surface temperature anomalies (to May) shows a similar pattern in May compared to those for April.

Weak positive anomalies persist across most of the top 100 m of the sub-surface, with most of this region within half a degree of average. Below 100 m depth, weak cool anomalies persist, with some parts of the sub-surface up to two degrees cooler than average.

Temperatures for the five days ending 9 June show waters are slightly warmer than average in the shallow sub-surface of the eastern equatorial Pacific, with waters in the top 50 m to 100 m reaching more than three degrees warmer than average in a small region. Compared to two weeks ago, temperature anomalies in this area have slightly increased.

Elsewhere temperatures were close to average.

Product code: IDCKGEWW00