NSW Seasonal Conditions Summary July 2016

Highlights

  • Most of state experienced well above average rainfall during June, with some areas recording their wettest June on record.
  • The rainfall outlook for July to September indicates wetter than normal conditions are likely across NSW. Cooler daytime temperatures are likely. Overnight temperatures are likely to be cooler in the west, north and along most of the coast, but there is a near-equal chance of cooler or warmer than normal overnight temperatures in the southern and some central areas of NSW.
  • During July, wetter than normal conditions are likely with cooler than normal daytime temperatures. There is a near-equal chance of cooler or warmer than normal overnight temperatures across most of NSW, with cooler overnight temperatures across the north and along the coast.
  • The Pacific Ocean is in an ENSO-neutral state. A negative IOD event is occurring, contributing to a greater likelihood of wetter than normal conditions and cooler daytime temperatures. Many global climate models suggest a borderline or weak La Niña event is possible during winter and spring. The Bureau of Meteorology’s ENSO outlook status remains at La Niña watch.
  • Topsoil moisture levels were high across NSW during June, with particular improvements in subsoil moisture across western, southern and south eastern NSW.
  • Pasture growth slowed due to the cool, wet and cloudy conditions, but was above average across the far west, central and southern NSW. Stock condition remains good, but supplementary feeding has been necessary in many areas to maintain condition and reduce the risk of nutritional disorders.
  • Early sown winter crops are performing well. Trafficability problems continue to delay weed and insect pest control and topdressing. Late sown crops have suffered the most from waterlogging, with seed bursting also a problem.
  • Significant run off occurred during the month, with farm water storages replenished in most areas.

Overview

June proved an extremely wet month, with 88 per cent of NSW experiencing above average rainfall. Rainfall was near-average in some areas of south western NSW, but well above average to extremely high across most of the remainder of NSW. Two East Coast Lows contributed to heavy rainfall along areas of the coast and the adjacent ranges. Most of the state received rainfall of 200 per cent of average for the month, with some areas receiving more than 400 per cent of average. A number of areas, particularly in central NSW, experienced the wettest June on record.

Although the cool, wet and cloudy conditions slowed the rate of pasture growth, it continued to improve across NSW. Particular improvements in growth occurred across the coast, but also areas of the north west, central west and northern tablelands.

Relative to historical records, June pasture growth was above average across most of the far west, central west and southern NSW. It was average to above average across areas of the tablelands and the north west, and generally average across the coast. Other pasture growth models indicated well above average to extremely high growth across most of the state.

Pasture biomass levels remained low in the east, but improved across most of central, southern and western NSW and across areas of the north west. Relative to historical records, biomass was generally average across most of the state, but above average across areas of the central west, southern tablelands and south west slopes.

Stock condition remains reasonably good. Supplementary feeding is continuing due to the cold, wet conditions increasing energy requirements, as well as the currently high moisture content of pastures and dual purpose crops. Stock health issues have been occurring including grass tetany, pregnancy toxaemia, hypocalcaemia, foot scald and bloat.

Winter crops are generally performing well, although widespread damage has occurred from waterlogging in low lying areas. Late sown crops have been worst affected, with seed bursting occurring where heavy rainfall followed shortly after sowing. Conditions have been too wet for resowing and have restricted topdressing, weed and insect pest control. Weed control remains a priority due to the lack of control opportunities prior to sowing. Insect pests have caused more problems than normal, particularly on early sown crops and establishing pastures. Grazing of dual purpose cereals is continuing, but in many cases stock have had to be removed due to the extremely wet conditions. Growth has slowed due to the wet, cold and cloudy conditions.

Topsoil moisture was at high levels across most of NSW during June, as a result of the wet conditions. Eastern and northern NSW showed the greatest increases over May. Relative to historical records, topsoil moisture was generally well above average to extremely high across the state.

Subsoil moisture levels improved during June, particularly in areas of western, southern and south eastern NSW. Relative to historical records, subsoil moisture in these areas was well above average to extremely high. Levels across the remainder of NSW were generally average.

Significant run off occurred during June, particularly in areas of eastern, central and southern NSW. To the end of June, yearly run off was well above average in these areas, although some areas of low run off remained in the north west, northern tablelands and south west.

NSW Seasonal Conditions Report – July 2016

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Seasonal outlook

The Bureau of Meteorology’s rainfall outlook for July to September (see table) indicates that wetter than normal conditions are likely across NSW, with cooler than normal daytime temperatures. Cooler than normal overnight temperatures are likely for areas of the far west, north west, northern tablelands, lower Hunter valley, central to north coast and areas of the south coast and southern tablelands. Warmer than normal overnight temperatures are likely in the far south east. There is a near-equal chance of cooler or warmer than normal overnight temperatures across the remainder of NSW.

During July, wetter than normal conditions are likely across NSW with cooler than normal daytime temperatures. There is a near-equal chance of cooler or warmer than normal overnight temperatures across most of NSW. Cooler than normal overnight temperatures are likely across areas of northern NSW, most of the coast and areas of the southern tablelands and Monaro.

The NOAA Climate Forecast System (CFS) rainfall outlook for July to September indicates wetter than normal conditions are likely for NSW. The overall temperature outlook is near-neutral, with cooler than normal conditions likely for areas of the far south west.

For July, the CFS rainfall outlook is near-neutral for most of NSW, with wetter than normal conditions likely for areas of the far south west. Warmer than normal conditions are likely over the eastern half of NSW and areas of northern NSW. There is a near-neutral outlook for the western half of NSW.

A survey of the major climate models in late June indicated most favour a wetter than normal rainfall outlook for July to September. One favours a near-neutral outlook and two drier than normal conditions. The majority indicated that warmer than normal conditions are likely for the period, with one favouring near-neutral outlook and three cooler than normal conditions.

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

July –  September

10

1

2

8

1

3

August –  October

7

1

0

3

0

5

The AussieGRASS pasture growth outlook for July to September suggests that well above average growth is likely for most of western, southern and central NSW. Above average growth is also suggested for areas of the Monaro, the southern and central tablelands, the Sydney basin and the far north coast. Average to above average growth is suggested for much of eastern NSW. Generally below average growth is suggested for the far south west and areas of the south and south east.

The seasonal rainfall prediction that the growth outlook is based upon is for slightly below average rainfall for most of NSW, but near-average rainfall for most of the coast and areas of the far west. This was based on a near-zero SOI phase during May and June. The rainfall outlook is quite different from that of the Bureau of Meteorology. The pasture growth outlook has moderate to high accuracy for most of the state. Due to the differences between the rainfall outlooks, the growth outlook may be an underestimate in some areas.

El Niño Southern Oscillation (ENSO)

The Pacific Ocean remains in an ENSO-neutral state. Sea surface temperatures in the central equatorial Pacific are at near-normal levels, near-average to below average in the east and above average in the west.

A strong negative Indian Ocean Dipole event is occurring in the Indian Ocean, which means there is greater likelihood of above-average rainfall and cooler daytime temperatures for south-eastern Australia during winter and spring. Trade winds across the equatorial Indian Ocean were reversed during June, consistent with such an event and contributing to moisture flow towards and across Australia.

The cool subsurface temperature anomaly extends from 100-150 m in depth to the surface or near the surface across the central to the eastern equatorial Pacific. It has weakened during the last month. Atmospheric indicators (including the SOI, Pacific trade winds and central Pacific cloud conditions) remain at normal or neutral levels.

Many global climate models suggest a borderline or weak La Niña event is likely to occur during winter and spring. The Bureau of Meteorology’s ENSO outlook status is at La Niña watch, as is that of the CPC/IRI.

Both La Niña and negative IOD events increase the chances of above-average rainfall across NSW during winter and spring.

Warm sea surface temperatures exist to the north, east, north east and north west of the continent and across much of the Indian Ocean. Cloud remains high over areas of western Indonesia. These areas remain potential sources of moisture for winter rainfall. Cool temperatures have developed in the far west of the Indian Ocean along the north east coast of Africa. The sub-tropical ridge is somewhat further north than normal. These are also positive indicators for winter rainfall. The southern annular mode is weakly positive.

Climatic outlook summary

NSW Seasonal Outlook (BoM)

Current outlook

Previous outlook

Quarterly Rainfall

Wetter

Wetter

Quarterly Maximum Temperature

Cooler

Cooler

(western, central and southern NSW, areas of north west, central and southern tablelands)

Near neutral

(eastern NSW, northern slopes, northern tablelands, Hunter valley)

Warmer

(far south east, coastal strip of Illawarra, central and far north coast)

Quarterly Minimum Temperature

Cooler

(areas of the far west, north west, central west, northern tablelands, central to north coast, lower Hunter valley, south coast & southern tablelands)

Near neutral

(far south, Riverina, central tablelands, areas of north west, southern tablelands & central west)

Warmer

(far south east)

Warmer

(most of NSW)

Near neutral

(far west)

El Niño Southern Oscillation (ENSO)

ENSO (overall)

Neutral

La Niña possible in winter/spring

Neutral

La Niña possible in winter/spring

BoM ENSO Outlook Status

La Niña watch

La Niña watch

SOI

Neutral (borderline positive, slowly trending to positive)

Neutral

Pacific Ocean (NINO3.4)

Neutral

(trending to cool)

Neutral

(likely to be cool in winter/spring)

Indian Ocean (IOD)

IOD negative

Warm Indian Ocean sea surface temperatures. Trade wind reversal.

IOD neutral

(DMI value currently negative, negative IOD event likely in late winter)

Warm Indian Ocean sea surface temperatures

Southern Annular Mode (SAM/AAO)

Weakly to moderately positive

(trending between neutral-weakly positive)

Weakly positive

(trending to weakly-moderately positive)

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

Rainfall and temperature

During June, rainfall ranged from 10-694 mm across the state with most of the state receiving 50-200 mm.

The far west received between 10-100 mm, with the eastern edge receiving 100-200 mm. The majority of the south, central west, north west, upper Hunter valley and tablelands received 50-200 mm. The coast, adjacent areas and the alpine areas received 100-600 mm, with most of these areas receiving 200-400 mm.

East Coast Lows in early and late June caused heavy rainfall, strong winds and flooding along coastal areas.

Most of the state received rainfall of 200 per cent of average for the month, with some areas receiving more than 400 per cent of average.

Daytime temperatures during the month were average to above average in the east, but generally average to below average across most inland areas. Overnight temperatures were warmer than normal, particularly in inland areas, with the exception of the first week of June. Some areas recorded their warmest overnight temperatures for June. Overnight temperatures were near normal in the far south west.

Relative rainfall

Relative to historical records, rainfall during June was above average across 88 per cent of the state. The far south west received near-average relative rainfall. The rainfall across most of the state ranked in the highest 10-20 per cent of years. A severe East Coast Low in early June caused widespread heavy rainfall and flooding in coastal areas, with another event developing late in the month.

Quarterly relative rainfall was above average across 84 per cent of NSW. Areas of the far south west, north west, northern tablelands, mid-north north coast, lower Hunter valley and the Sydney basin received near-average rainfall for the period. Most of the state’s rainfall ranked in the highest 10-20 per cent of years.

Soil moisture

Topsoil moisture remained high during June, particularly in the central, southern, south eastern and coastal areas of the state and across some areas of the north west.

Relative to historical records, June topsoil moisture levels were well above average to extremely high across much of NSW (ranking in the highest 10-20 per cent of years). There was near-average topsoil moisture across some areas of the coast and the Hunter valley.

Subsoil moisture levels improved during June, particularly across areas of central, southern, south eastern and coastal NSW. Relative to historical records, subsoil moisture was above average to extremely high across areas of far western, central, southern and south eastern NSW. It was near-average across the remainder of the state, but low in some areas of the north coast and northern tablelands until the end of the month.

Streamflow

Significant run off occurred during June across most of NSW, particularly in areas of central, southern, south eastern and coastal NSW. Run off was also high across the central and southern tablelands and areas of the northern tablelands.

Yearly run off to June was high across areas of the central west, Riverina, far south, south east and the eastern edge of the far west. It was near-average across most of the remainder of NSW, but below average in the eastern areas of the north west, the north and east of the northern tablelands and across some areas of the upper Hunter valley and far west.

The Bureau of Meteorology's streamflow forecast indicates high streamflows are likely across most NSW monitoring stations during July to September, with some sites having a near-equal probability of high or near-median streamflows.  Near-median streamflows are likely at some northern sites, and low streamflows are likely at a small number of sites across NSW.

Relative pasture growth and biomass

Relative to historical records, AussieGRASS modelled pasture growth during June was above average across most of the far west, central west and south. It was also average to above average across areas of the tablelands and the north west, and generally average across the coast. Other pasture growth models indicated well above average to extremely high growth across most of NSW.

Over the quarter, AussieGRASS relative growth was above average across 41 per cent of the state and average over most of the remainder. Areas of above average growth occurred across the far west, central west, south west slopes and the southern tablelands. Areas of below average growth occurred across the south to mid-north coast, Hunter valley and areas of the northern tablelands.

During June, relative biomass levels were generally average across most of the state, but above average across areas of the central west, southern tablelands and south west slopes. Relative biomass remained low across areas of north western NSW, the northern tablelands, the upper Hunter valley and areas of the coast and far south west.


Figure 1: Relative monthly topsoil moisture

Figure 1. Relative monthly topsoil moisture

Figure 2: Relative quarterly pasture growth

Figure 2. Relative quarterly pasture growth

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 Australian Export Grains Innovation Centre, 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 8 July 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 (8 July 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.