Southern NSW - Fast Break

Welcome to your Fast Break newsletter

You are reading the Fast Break for New South Wales

Volume 1 | Issue 1 | New South Wales | Published: 04 February 2019

Welcome to the first edition of our “Fast Break” newsletter for the Southern New South Wales grains industry. We have been constructing these summaries for the last 11 years in Victoria, and for the last year in South Australia and Tasmania as part of the GRDC funded “Using Seasonal Forecasts Project” project. If you like it, please consider passing it on through your networks and subscribing.

We are describing SNSW as a line south of Dubbo. In the predictions, I divide this region into quarters, hence N, S, E, W, NW, NE, SW, SE, defines zones in this southern half. If the models are more precise I might use terms such as coast, Riverina, central west, etc.

A weak El Niño like ocean appeared in November and December 2018. Despite the central Pacific Ocean and surface interested in the concept of El Niño the atmosphere above in terms of pressure, cloud and wind patterns weren’t having a bar of it. Consequently, the attempt rapidly collapsed to neutral over January. But, a risk still remains that it could come back properly this year.
Current indicators are neutral, or in the case of cloud and tradewinds weakly El Niño.
Similarly, to the same time in 2015, a large slug of warm water remains at depth in the western Pacific. Trade wind reversals to the east of PNG will need to be watched in coming months, as we don’t want to see westerly wind bursts force that warm water over to South America and kick off a more serious El Niño. Current model forecasts suggest a weak one can hang around over autumn but most think it will collapse in winter. Bare in mind, model skill at this time is poor as it will be essentially random weather around PNG that may or may not kick off a potential ElNiño.
The one climate indicator that has been active over summer, has been a positive phase of the Southern Annular Mode. This can increase rainfall in the SE of NSW over summer. This looks to have had some effect in December and January but providing average rainfall to this region rather than wetter.
Pressure position and strength have been generally behaving themselves. A persistent high pressure in the Tasman Sea has stopped the passage of fronts, but allowed some troughing of tropical moisture, particularly to the Central West and a lot of warm air down from the north, increasing temperatures.
Modelled rainfall predictions for SNSW are split between drier and average, but there is a strong model consensus for a continuation of warmer temperatures.

Model consensus forecast for the next six months