NSW Seasonal Conditions Summary November 2016

Overview

Rainfall across NSW returned to a more normal pattern during October after record wet conditions during winter and early spring. About 75 per cent of the state received near-average rainfall during October, with 17 per cent experiencing above average rainfall.

Pasture growth during October declined in areas of the far west, north coast and Sydney basin but generally remained moderate to high during the month. Relative to historical records, October pasture growth was average across most of western NSW, with some area of high growth. Growth was generally average to above average across the north west, central west, Riverina, far south and the tablelands. The Sydney basin and the far north coast had areas of below average growth, with growth across the rest of the coast being near-average.

Other temperate pasture growth models indicated generally above average to extremely high relative growth across most of inland NSW during October.

Pasture biomass levels were stable or improved across NSW. Increases in biomass occurred across areas of the tablelands and south east. Relative to historical records, biomass was above average to extremely high across most of the state. Fodder conservation is underway, being assisted by the drier conditions. While quantities are generally above average, quality may be lower than normal in some areas.

Stock condition is generally very good. Foot problems, bloat and increased worm burdens continue to be issues.

The cool, overcast conditions and slower growth during winter are likely to benefit canola oil content. Winter crop maturity is about one to two weeks later than normal in most areas. Harvest has commenced in the north of the state for canola and barley. Windrowing of canola is commencing in other areas. Where crops have not been stressed, waterlogged or inundated yield potential generally remains average to above average. Early sown crops and those where waterlogging was minimal generally have above average yield potential, although protein levels in cereals are likely to be lower than normal. Waterlogging and disease have affected pulse crop yield potential. Around 10-30 percent of winter crop area has been lost due to waterlogging and inundation.

Cotton planting has been mostly completed in the north. In the south, difficulties in ground preparation and weed control may result in the area sown to summer crops being less than expected. Rice sowings have mostly been completed.

Topsoil moisture declined during October but remained at moderately high levels across areas of the south, Riverina, central west, north west, tablelands and south east. Relative to historical records, October topsoil moisture levels were above average across most of inland NSW, but average to below average along the coast.

Subsoil moisture levels remained relatively stable. Relative to historical records, subsoil moisture levels remained extremely high across most of inland NSW, but average across the coast.

Above average run off occurred during October across areas of southern and central NSW. Run off was low across areas of the coast and the north west. Yearly run off to October remained above average to extremely high across most of inland NSW.

NSW Seasonal Conditions Report – November 2016

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Seasonal outlook

The Bureau of Meteorology’s rainfall outlook for November to January (see table) indicates that there is a near-equal probability of drier or wetter than normal conditions across most of NSW. Drier than normal conditions are likely in the far north east. There is a near-equal probability of cooler or warmer than normal daytime and overnight temperatures across most of NSW. Warmer than normal daytime temperatures are likely across areas of the far west, south west, far south east, far north east and the Illawarra to mid-north coast. Warmer than normal overnight temperatures are likely across much of eastern NSW, the central and southern tablelands, Monaro, and areas of the Riverina and the central west.

During November, drier than normal conditions are likely for most of NSW. The major influence on this outlook is the currently negative southern annular mode. There is a near-equal chance of drier or wetter than normal conditions for areas of the central to mid-north coast, lower Hunter valley, northern tablelands and most of the north west. Warmer than normal daytime temperatures are likely, with warmer overnight temperatures across the coast, north, north west, central west, northern and central tablelands and Hunter valley.

The NOAA Climate Forecast System (CFS) rainfall outlook for November to January is near-neutral for NSW. The overall temperature outlook is also near-neutral.

For November, the CFS rainfall outlook is also near-neutral. The temperature outlook is near-neutral for most of NSW, but warmer than normal along areas of the coastal strip and cooler in some areas of the south east.

A survey of the major climate models in early November indicated half favoured a generally near-neutral rainfall outlook (that is, a near-equal chance of drier or wetter than normal conditions) for the November to January period, with four (29 per cent) favouring a generally wetter outlook and three (21 per cent) a generally drier outlook. For temperature, most models (46 per cent) favoured a generally near-neutral outlook, with about 38 per cent favouring a warmer than normal outlook and about 15 per cent favouring a cooler than normal outlook.

Overall NSW outlook -
major climate models
Rainfall Outlook
(number of models)
Temperature Outlook
(number of models)
Period Generally wetter Generally near-neutral Generally drier Generally warmer Generally near-neutral Generally cooler
November – January 4 7 3 5 6 2
December – February 2 6 2 4 5 1

The AussieGRASS pasture growth outlook for November to January suggests that below average pasture growth is likely in most areas of NSW. However, this is likely to be due to the model assuming limited remaining soil nitrogen. Near-average growth is suggested for areas of central and southern NSW.

The seasonal rainfall prediction that the growth outlook is based upon is for a near equal chance of above or below median rainfall for most of NSW, with some wetter areas across the north west and coast, and some drier areas across central and southern NSW. This was based on a rapidly falling SOI phase during September and October. The Bureau of Meteorology’s rainfall outlook suggests a near-equal chance of drier or wetter than normal conditions across most of NSW. The growth outlook has moderate to high past accuracy for the coast and far south, but accuracy is low across most of NSW.

El Niño Southern Oscillation (ENSO)

The Pacific Ocean remains in an ENSO-neutral state. Most models suggest a neutral conditions continuing for the remainder of spring and into summer, although with cooler than average sea surface temperatures in the central equatorial Pacific. A La Niña event is less likely, although some models suggest a weak, short-lived event is possible during summer.

Sea surface temperatures are below average in the central and eastern-central equatorial Pacific and near-average but variable in the east. La Niña-like above average sea surface temperatures are present in the western equatorial Pacific to the north of Australia. Cloud conditions and recent trade wind activity suggest stronger Walker circulation, indicative of some La Niña-like atmospheric coupling.

The negative Indian Ocean Dipole (IOD) event is nearly at an end. The Dipole Mode Index (DMI) recently weakened to neutral levels with the onset of the monsoon. Continued warm sea surface temperatures near Sumatra and to the north of Australia may provide potential moisture for NSW if the right conditions occur.

During October cloud remained high over Australia, Papua New Guinea and Indonesia, particularly near Sumatra.

A cool subsurface temperature anomaly extends across the equatorial Pacific, reaching the surface across the central and eastern areas. It has weakened in the west, where weak warm anomalies are present.

The easterly Pacific trade winds were near average over the month, except for a small area in the western Pacific. They strengthened across the western equatorial Pacific in late October and early November, which may contribute to more cooling of sea surface temperatures in the central Pacific. However, this is likely to be a short-term effect of the passage of the Madden-Julian Oscillation and trade winds are likely to return to normal afterwards. The SOI returned to neutral levels during mid-October.

Cloud conditions near the junction of the equator and the International Date Line remained low.

The Bureau of Meteorology’s ENSO outlook status remains at La Niña watch. The CPC/IRI has shifted from La Niña watch to a La Niña advisory, suggesting that La Niña conditions are present and slightly favoured to persist through summer. Note that the Bureau and CPC/IRI use different thresholds for such events.

The sub-tropical ridge is slightly further north than normal. The southern annular mode (SAM) has returned to moderately negative levels, with westerly winds and high pressure systems moving further north than normal. During spring and summer this can result in drier than normal conditions, as this acts to prevent moisture being drawn from the north. The negative SAM is one of the major influences on the drier than normal outlook for November.

Climatic outlook summary

NSW Seasonal Outlook (BoM)

Current outlook

Previous outlook

Quarterly Rainfall

Near neutral

(most of NSW)

Drier

(areas of far north eastern NSW)

Wetter

(most of NSW)

Near neutral

(areas if the northern tablelands and north coast)

Quarterly Maximum Temperature

Near neutral

(most of NSW)

Warmer

(areas of the far west, south west, far south east, Illawarra to mid-north coast and far north east)

Cooler

Quarterly Minimum Temperature

Near neutral

(most of NSW)

Warmer

(most of eastern NSW, southern & central tablelands, Monaro, central west & areas of the Riverina)

Cooler

(most of NSW)

Near neutral

(far south eastern NSW)

El Niño Southern Oscillation (ENSO)

ENSO (overall)

Neutral

La Niña possible but unlikely

Neutral

La Niña possible but unlikely

BoM ENSO Outlook Status

La Niña watch

La Niña watch

SOI

Neutral

Positive

Pacific Ocean (NINO3.4)

Neutral

(cool)

Neutral

(cool)

Indian Ocean (IOD)

Negative IOD is weakening – trending to neutral

IOD slightly negative – borderline neutral

Southern Annular Mode (SAM/AAO)

Moderately to strongly negative

Moderately negative

(trending from moderately negative to near neutral)

Note: Climate model outlooks are updated regularly. To check whether updates are available, use the hyperlinks provided.

NSW Climate Summary

Rainfall and temperature

Rainfall was near average across much of inland NSW during October, but above average across areas of the north west, central west and tablelands. Rainfall was below average across the south to central coast and the far north coast. Rainfall in these areas was less than 40 to 60 per cent of average.

Rainfall across the state ranged from 9-419 mm. The far west generally received 10-25 mm, with lesser falls in the far north west. The remainder of the state generally received 25-100 mm. There were higher falls in the alpine areas, some areas of the southern tablelands and the upper Hunter valley.

Daytime temperatures were well below average during the month across inland NSW, with overnight temperatures below average across most of NSW.

Relative rainfall

Relative to historical records, rainfall during October was average across 75 per cent of the state and above average across 17 per cent.  Above average relative rainfall was restricted to areas of the north west, tablelands, upper Hunter valley, the north east of the central west, and areas in the east of the Riverina and the far south. Below average relative rainfall occurred across areas of the north coast, Sydney basin, Illawarra, south coast, Monaro and the eastern areas of the southern tablelands.

Quarterly relative rainfall was above average across 90 per cent of the state. It was extremely high across most of inland NSW, and was above average across areas of the north coast and upper Hunter valley. The majority of the coast, Monaro and the east of the southern tablelands had generally average relative rainfall. A small area of the south coast had below average relative rainfall for the period.

Soil moisture

Topsoil moisture declined during October, but still remained at moderately high levels across areas of the south, Riverina, central west, north west, tablelands and south east. Topsoil moisture declined the most in areas of the far west, north coast and Sydney basin.

Relative to historical records, October topsoil moisture levels were above average across most of inland NSW. Relative topsoil moisture was extremely high across areas of the far south, eastern Riverina, southern and central tablelands and areas of the central west and north west. The coast had generally near-average topsoil moisture, with areas that were below average across areas of the north coast, Sydney basin and Illawarra.

Subsoil moisture levels remained relatively stable, improving over some areas of the south and declining slightly from very high levels across the central and southern tablelands and south west slopes. Relative to historical records, levels remained extremely high across most of inland NSW, but average across the coast and the east of the northern tablelands.

Streamflow

Above average run off occurred during October across areas of southern and central NSW. Run off was low across areas of the north coast, Sydney basin, south coast and the north west.

Yearly run off to October remained above average to extremely high across most of inland NSW, with the exception of areas of the north west, the far south west, the east of the northern tablelands and the mid-north to north coast.

The Bureau of Meteorology's streamflow forecast indicates high streamflows are likely across most NSW monitoring stations during November to January. Median to high flows are likely at some northern locations, with low to median flows likely at some coastal locations.

Relative pasture growth and biomass

Relative to historical records, AussieGRASS modelled pasture growth during October was average across most of western NSW, with areas of above average growth in the far north west. Growth ranged from average to generally above average across the north west, central west, Riverina, far south and the tablelands. The coast and the Hunter valley had generally average growth, with areas of below average growth across the Sydney basin and far north coast.

Other pasture growth models indicated above average to extremely high relative pasture growth across most of western, southern, central and north western NSW. Growth in the tablelands ranged from average in the east to above average or extremely high in the west. Growth across the majority of the coast and Monaro was near-average, with areas of below average growth over the far north coast, the Sydney basin, the alpine areas and some areas of the southern tablelands.

Over the quarter, AussieGRASS relative growth was above average across 67 per cent of the state and average across most of the remainder. Areas of near-average growth occurred in the eastern areas of the far west, the west of the Riverina and across areas of the coast.

During October, relative biomass levels remained well above average to extremely high across most of the state. The highest levels were across areas of the far west, the central west, north west, northern tablelands and areas of the Riverina and far south. Areas of the south coast and Sydney basin had near-average relative biomass.

Figure 1: Relative monthly topsoil moisture

Soil moisture map

Figure 2: Relative quarterly pasture growth

Pasture growth map

More information

For more information, contact the NSW Department of Primary Industries on 02 6391 3100 or Local Land Services on 1300 795 299.

Acknowledgements

Information used in this report was sourced from the Australian Bureau of Meteorology, CSIRO, the Queensland Department of Science, Information Technology and Innovation, the Queensland Alliance for Agriculture and Food Innovation, the U.S. Department of Agriculture, U.S. Department of Commerce, the U.S. National Oceanic and Atmospheric Administration, the International Research Institute for Climate and Society (Columbia University), the UK Meteorological Office, the APEC Climate Centre, NSW Local Land Services and NSW Department of Primary Industries.

External links

Disclaimer

The seasonal outlooks presented in this report are obtained from the Australian Bureau of Meteorology and other sources. These outlooks are general statements about the likelihood (chance) of (for example) exceeding the median rainfall or minimum or maximum temperatures. Such probability outlooks should not be used as categorical or definitive forecasts, but should be regarded as tools to assist in risk management and decision making. Changes in seasonal outlooks may have occurred since this report was released. Outlook information was up to date as at 11 November 2016.

Recognising that some of the information in this document is provided by third parties, the State of New South Wales, the author and the publisher take no responsibility for the accuracy, currency, reliability and correctness of any information included in the document provided by third parties.

The information contained in this publication is based on knowledge and understanding at the time of writing (11 November 2016). However, because of advances in knowledge, users are reminded of the need to ensure that information upon which they rely is up to date and to check currency of the information with the appropriate officer of the Department of Primary Industries, Local Land Services or the user’s independent adviser.