ENSO Update

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Bulletin September 2017 - Summary

The El Niño–Southern Oscillation (ENSO) remains neutral. The surface of the tropical Pacific has warmed over the past fortnight as a result of weaker trade winds. This has reversed the cooling trend that had been observed since mid-winter. While sea surface temperatures remain well within the neutral range, anomalously cool water persists below the surface.
International climate models surveyed by the Bureau suggest this recent surface warming may only be temporary, with further cooling of the tropical Pacific Ocean likely. Five of the eight models suggest sea surface temperatures will reach La Niña thresholds by December 2017, but only three maintain values for long enough to be classified as a La Niña event.
While unusual, it is not unheard of to see La Niña develop this late in the year. Of the late-developing La Niña events, their effect on summer rainfall has been mixed, with some leading to widespread above-average falls across eastern Australia, and others having minimal effect. The current 3-month rainfall outlook suggests only a 50% likelihood of wetter conditions in many parts of the country.
The Indian Ocean Dipole (IOD) remains neutral. Three of the six climate models surveyed suggest positive IOD thresholds may be reached during spring, but these positive values would be short-lived as IOD events naturally decay by December.

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Bulletin September 2017 - El Nino Oscillation

The El Niño–Southern Oscillation (ENSO) remains neutral. The surface of the tropical Pacific has warmed over the past fortnight as a result of weaker trade winds. This has reversed the cooling trend that had been observed since mid-winter. While sea surface temperatures remain well within the neutral range, anomalously cool water persists below the surface.

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Bulletin September 2017 - MJO

The Madden-Julian Oscillation is currently active over the maritime continent. According to the NCEP and BOMM model, it will continue to move eastwards to the Western Pacific this month of October and remaining during November this year.

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Note: Due to frequent images update from source provider, the quoted Sources might not give the same images as shown

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Bulletin September 2017 - Cloud

The outgoing longwave radiation (OLR) indicates below normal cloud to normal cover over the Tropical Equatorial Pacific, and extending over parts ofthe Western southern Pacific in the next coming three months.

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Note: Due to frequent images update from source provider, the quoted Sources might not give the same images as shown

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Bulletin September 2017 - Rainfall

Below normal to normal rainfall is indicated by TRMM over the Tropical Equatorial Pacific and over Western southern Pacific in he past month of September.

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Note: Due to frequent images update from source provider, the quoted Sources might not give the same images as shown

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Bulletin September 2017 - SST

The sub-surface temperatures profile in the past three months showed normal to below normal temperatures over Equatorial Pacific. Weak warm anomalies are observed over South Western Pacific. During August and September enhanced cooler anomalies are evident over the equatorial Pacific, while for South West Pacific temperatures remain near- normal.

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Note: Due to frequent images update from source provider, the quoted Sources might not give the same images as shown

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Bulletin September 2017 - MSLP

Normal mean sea level pressure(mslp) over the Equatorial Pacific. Normal to above normal mean-sea-level pressures evident over much of the Southern Pacific. Below normal mslp over South of New Caledonia.

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Note: Due to frequent images update from source provider, the quoted Sources might not give the same images as shown

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Bulletin September 2017 - Model Outlooks

The four main dynamic models outlooks on NINO3.4 are indicating cool SST anomalies over the Equatorial Pacific for the remainder of this year. Warm SST anomalies are expected early 2018, along the Equatorial Pacific.

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Bulletin September 2017 - SPCZ

Currently unavailable!

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