North Australian FISH FINDER TM forums

http://www.bom.gov.au/climate/enso/wrap-up/ from Sept 13 ...

The Bureau's ENSO Outlook has been raised to LA NIÑA.

Key atmospheric and oceanic indicators of the El Niño–Southern Oscillation (ENSO) show an established La Niña. Tropical Pacific sea surface temperatures have been cooling since June and are now at La Niña thresholds. Atmospheric indicators including the Southern Oscillation Index (SOI), trade wind strength, and equatorial cloudiness are also displaying patterns typical of a La Niña event.

Models indicate this La Niña event may peak during the spring and return to neutral conditions early in 2023. La Niña events increase the chances of above-average rainfall for northern and eastern Australia during spring and summer.

The negative Indian Ocean Dipole (IOD) event continues. The IOD index has satisfied negative IOD thresholds (i.e. at or below −0.4 °C) since June, with the latest weekly value being −0.8 °C. All surveyed climate models agree that negative IOD conditions are likely to continue into late spring. A negative IOD event is typically associated with above average spring rainfall for much of Australia. When a La Niña and negative IOD combine, it further increases the likelihood of above average rainfall over Australia, particularly in the eastern half of the continent.

The Southern Annular Mode (SAM) is currently in a positive phase and is likely to be mostly positive for the coming three months. During the spring months, a positive SAM has a wetting influence for parts of eastern New South Wales and far eastern Victoria, but a drying influence for western Tasmania.

The Madden–Julian Oscillation (MJO) continues to show a weak signal with most models suggesting it will remain weak for at least the next seven days. A weak MJO is unlikely to have much impact on Australian climate.

Climate change continues to influence Australian and global climate. Australia's climate has warmed by around 1.47 °C for the 1910–2020 period. Southern Australia has seen a reduction of 10–20% in cool season (April–October) rainfall in recent decades. There has also been a trend towards a greater proportion of rainfall from high intensity short duration rainfall events, especially across northern Australia.

Graphic ... http://www.bom.gov.au/climate/enso/outlook/

Will the NT get a good Wet this year? Or a dud?

La Nina-IOD combo to persist until early 2023, says BOM ...

La Niña continues in the tropical Pacific, and is likely to persist into early 2023.

Both atmospheric and oceanic indicators of the El Niño–Southern Oscillation (ENSO) are consistent with an established La Niña, including tropical Pacific sea surface temperatures, the Southern Oscillation Index (SOI), trade wind strength, and equatorial cloudiness.

Models indicate the La Niña is likely to decline over spring, with a return to ENSO-neutral conditions (neither La Niña nor El Niño) early in 2023. Sea surface temperatures in the tropical Pacific remain similar, compared to two weeks ago. The SOI remains well above La Niña thresholds.

La Niña typically increases the chance of above average rainfall for northern and eastern Australia during spring and summer.

The negative Indian Ocean Dipole (IOD) event also continues. The IOD index has satisfied negative IOD thresholds (i.e. at or below −0.4 °C) since June. Models indicate that the negative IOD is likely to persist until late spring. A negative IOD typically increases the chance of above average spring rainfall for most of the eastern two thirds of Australia.

The Southern Annular Mode (SAM) is currently in a positive phase and is likely to remain generally positive throughout spring into early summer. During the spring and summer months, a positive SAM increases the chance of above average rainfall for parts of eastern New South Wales, eastern Victoria, and south-eastern Queensland, and increases the chance of below average rainfall for western Tasmania.

The MJO is moving into the western Pacific Ocean and is forecast to strengthen further in the coming fortnight as it tracks further east. Its influence at this time of the year may lead to above-average rainfall for parts of eastern Australia, and briefly reduce the strength of equatorial trade winds west of the Date Line.

When La Niña and negative IOD conditions combine, the likelihood of above average rainfall over Australia is further increased, particularly for the eastern half of the continent. The Bureau of Meteorology's extended and long-range forecasts show that above average rainfall is likely across much of eastern Australia. This reflects the influence of several key climate drivers.

Climate change continues to influence Australian and global climate. Australia's climate has warmed by around 1.47 °C for the 1910–2020 period. There has also been a trend towards a greater proportion of rainfall from high intensity short duration rainfall events, especially across northern Australia.

from ... http://www.bom.gov.au/climate/enso/