NSW State Seasonal Update - October 2023



Prepared by NSW DPI

NSW overview

Drought conditions continue to expand impacting large areas of central, northern and eastern NSW.

  • The NSW DPI Combined Drought Indicator (CDI) shows that 52% of NSW is in one of the three drought categories at the end of October.
  • Over 40% of the North Coast Local Land Services region is in the Intense Drought category.
  • On ground conditions are consistent with the onset of a major drought in many regions across NSW.
  • Available field reports indicate that drought management including supplementary feeding of livestock is well underway in these regions.
  • Parts of southern NSW continue to have a strong production outlook, though consistent rainfall will be required to maintain current conditions.
  • Producers are continuing to monitor on-ground conditions and climate forecasts closely, while implementing actions in line with their individual drought strategies.

Current conditions

    Most of NSW received some rainfall in October with most regions recording low totals for the month.

  • October rainfall was average to below average for most of NSW.
  • Totals varied markedly across the state, with many areas in eastern, southern and central NSW receiving falls between 25 – 100mm.
  • High rainfall totals were recorded in isolated areas on the North Coast, Central Coast and parts of the Hunter in late October, with potential to ease drought conditions in these areas of NSW if there is further follow up rain. Weak to strong drying trends are evident across much of NSW leading to a decline in all drought indicators for many areas. The DPI continues to closely monitor conditions and encourages producers in these areas to seek advice where needed to minimise impact on production and farm operations.
  • Available remote sensing information of pasture conditions highlights that there is considerable variability within and between regions. This is typical of drought onset where soil nutrition and local climate variability can influence crop and pasture response as the landscape dries.
  • For further information on each Local Land Services region, see the Regional Breakdown section in this Update.

Seasonal Climate Outlook

    The outlook is for warm conditions to persist across NSW and moderate to high chance of above median rainfall for Northern NSW in the November to January period.

  • The rainfall forecasts are variable for NSW, indicating there is a 40 – 65% chance of average rainfall for the November 2023 to January 2024 period.
  • The ENSO Outlook status is at El Niño and the Southern Oscillation Index is negative.
  • The Indian Ocean Dipole (IOD) is currently positive.
  • Other climate drivers like the Southern Annular Mode (SAM) and local systems continue to bring the prospect of instability in week-to-week weather during this forecast period.

The CDI and its individual rainfall, soil moisture and crop/pasture growth metrics are leading biophysical indices of seasonal conditions and drought status. Other factors affecting production and economic responses usually lag the CDI. Further information about the correct interpretation of the CDI at a region and industry level is provided in the regional breakdown section of this report .

Figure 1. Verified NSW Combined Drought Indicator to 31 October 2023

It is important to recognise the CDI provides an aggregated view of NSW, and that on-ground conditions can be different to those displayed in the maps. They provide an ‘on average’ view of a particular region only.

Rainfall

Widespread rainfall during October

  • Most areas in eastern NSW received between 25 to 100mm of rainfall (Figure 2a). The highest monthly rainfall totals (above 100mm) were recorded in isolated locations on the east coast and southern highlands.

Calendar year to date rainfall is below average for many areas

  • For the calendar year to date, eastern NSW has received between 300 to 1000mm of rainfall. Areas around the southern highlands, and an isolated area north of Taree has received more than 1000mm. West of the Great Dividing Range has generally received rainfall between 100mm and 600mm (Figure 2b). Year to date rainfall has been average to very much below average for most of NSW.

Rainfall deficits compared to long term average

  • The rainfall anomaly data shows the difference between total October monthly rainfall and the long-term average monthly rainfall (1981 – 2010; Figure 2c). There has been a negative rainfall anomaly across much NSW during October. Parts of the North Coast, Hunter and southwestern NSW have recorded positive rainfall anomalies.

Figure 2a. Total rainfall October 2023

Figure 2b. Calendar year rainfall accumulation to 31 October 2023

Figure 2c. Rainfall anomaly – October 2023

Temperature

Higher than average maximum temperatures

  • In October, the average maximum temperatures ranged from 9°C in the southern alps to above 30°C in the northwest of NSW (Figure 3a).
  • Above average maximum temperatures were experienced across most central and eastern NSW in October. Maximum temperatures were generally between 1°C and 3°C above average (Figure 3b).

Higher than average minimum temperatures

  • Minimum temperatures were generally between 3°C and 12°C for most of NSW. The warmest temperatures (above 15°C) were in the far northwest of the state (Figure 3c).
  • Minimum temperature anomalies were generally between -2 and 0°C for most of NSW during October (Figure 3d). Cooler anomalies of more than -2°C occurred in parts of the central west of NSW.

Figure 3a. Average maximum temperature – October 2023

Figure 3b. Maximum temperature anomaly – October 2023

Figure 3c. Average minimum temperature – October 2023

Figure 3d. Minimum temperature anomaly – October 2023

Normalised Difference Vegetation Index (NDVI) Anomaly

The NDVI anomaly at 23 October indicate large parts of north-west, central and coastal NSW have poor vegetation condition.

  • The seasonal Normalised Difference Vegetation Index anomaly (NDVI, Figure 4) indicates that plant greenness levels are variable across NSW.
  • To the end of October, many areas had above normal plant greenness levels. Areas of below average plant greenness have continued to expand across the Central West, Hunter, North West, South East, North Coast, Central Tablelands and Western Local Land Services areas.
  • The monthly NDVI analysis has a closer resemblance to on-ground physical observations than long term drought indices like the CDI which summarise the last 12 months.
  • The low levels of plant greenness, relative to average, indicate low levels of ground cover and standing dry matter available for livestock. On ground reports support this observation, with low to very low ground cover being reported.
  • Close inspection of the NDVI data indicates farm to farm variability in plant condition within the drought areas identified by the NSW CDI.
  • Some of the extremely negative NDVI areas (brown patches) are water bodies.

Figure 4. Seasonal NDVI anomaly Aug 2023 to 23 October 2023

Tools for drought feeding livestock

NSW Department of Primary Industries’ Drought & Supp Feed Calculator app has been re-released to support NSW livestock producers with their decision making as seasonal conditions change.

The Drought & Supp Feed Calculator simplifies decision making for livestock producers by enabling users to assess pastures and work out feed requirement and if supplementary feeding is needed, compare different supplements and ration mixes, and calculate the costs of different feeding options.

Search for Drought & Supp Feed Calculator and download the application from your app store.

NSW Farm Dam Survey

Water availability is highly variable across NSW

  • The NSW Farm Dam Survey indicates dam levels have generally declined over the past few months (Figure 5).
  • Higher farm dam levels are present across many parts of central and southern NSW following on from recent rain events.
  • Low dam levels are evident along the NSW coast and hinterland. Large areas of Western NSW have dam levels below 60% capacity.
  • The farm dam assessment was not possible for some parts of NSW in October due to missing data.

Figure 5. Average parish-level farm dam extents between 13 Sept to 13 October 2023

NSW DPI Farm Tracker Reports

NSW DPI Farm Tracker Application reports are completed by users across NSW. On the ground reports submitted on the NSW DPI Farm Tracker application (Figure 5a) show producers in several regions are reporting they are managing mild to very severe drought conditions in September.

Figure 5a. NSW DPI Farm Tracker Reports - October 2023

Tools for farmers to monitor and report seasonal conditions

The Farm Tracker application is freely available and can be used to help monitor seasonal conditions on your property. Completing a report allows a user to create a geotagged photo diary, monitor dam levels, or record changes at an individual paddock level.

This information provides a detailed and visual record of a farm over time that can be invaluable for budgeting, planning and decision making. The data collected for each farm is not available for other people to see or search.

Reports are also used by NSW DPI as a highly valuable information source to ground truth products from the DPI Seasonal Conditions Monitoring Program. Farmers data remains anonymous in this use.

Search for NSWDPI Farm Tracker and download the application from your app store.

Soil Water Index

The Soil Water Index (SWI) shows conditions are variable across NSW.

  • Large areas of the North Coast, Northern Tablelands, North West, Hunter, Greater Sydney and South East LLS regions are showing Extremely Low soil water index values.
  • The area in the Below Average category has expanded since the September Update due to warm temperatures and low rainfall.
  • Substantial rainfall in many areas is needed to trigger an improvement in the SWI.

Figure 6. Soil Water Index (SWI) to 31 October 2023

Plant Growth Index

Plant Growth Index values continue to decline.

  • The Plant Growth Index (PGI, Figure 7) shows a decline in categories across all of NSW since the September Update.
  • The area in the Extremely Low category on the North Coast, Northern Tablelands, North West, Greater Sydney, South East and Hunter has expanded due to warn and dry conditions for much of October.

Figure 7. Plant Growth Index (PGI) to 31 October 2023

Rainfall Index

Rainfall Index values remain variable.

  • The Rainfall Index (RI, Figure 8) shows a decline in all categories since the September Update.
  • The area in the Below Average to Extremely Low categories has expanded in the northern and central parts of NSW.
  • Overall, on ground reports confirm the continued decline in the individual indices, with producers managing feed deficits and declines in crop yields due to rainfall deficits and low stored soil water in parts of NSW.

Figure 8. Rainfall Index (RI) to 31 October 2023

Drought Direction Index

Drying trend continues for most of NSW.

  • The Drought Direction Index (DDI, Figure 9) tracks the 150-day trend of the rainfall index.
  • Western NSW is generally showing a weak drying trend due to below average rainfall over the past few months. Large areas of eastern NSW are showing a strong drying trend.
  • Areas in the Weak and Strong Drying Trend category have experienced a drier September and October compared to previous months.
  • This trend, combined with the decline in the individual drought indicators reflects the deterioration of conditions and the onset or continuation of a major drought in these regions.

Figure 9. Drought Direction Index (DDI) to 31 October 2023

Changes in the individual drought indicators may have occurred since this update was released. For the most current information, please visit DroughtHub.

NSW outlook - November 2023 to January 2024

(issued 02 November 2023)

Variable rainfall forecast for NSW

  • The seasonal rainfall outlook indicates that there is a near average chance (between 40% to 60%) of median rainfall for most of NSW during the November to January period (Figure 10).
  • There is a slightly higher chance of above average rainfall in the central and north of NSW.
  • There is a slightly lower than average change of above average rainfall in the south, southwest and far northeast of the state.

Warm to hot conditions forecast to continue for NSW

  • The maximum temperature outlook indicates a more than 80% chance of exceeding median daytime temperatures across most of NSW during the November to January period (Figure 11).

Warmer nights across NSW

  • There is an above 80% chance of warmer than median overnight temperatures across most of eastern, central and northern NSW during the November to January period (Figure 12).
  • Across western and southwestern NSW there is a 60% to above 70% chance of above median overnight temperatures.

Prospect of unstable weather

  • Although the forecast is for near average rainfall for most of NSW and warmer temperatures for the three-month outlook, other climate drivers like the Southern Annular Mode (SAM) and warm local sea surface temperatures bring the prospect of unstable week to week weather during the forecast period.

Figure 10. Seasonal rainfall outlook for NSW issued on 02 November 2023

Figure 11. Seasonal average maximum temperature outlook for NSW issued on 02 November 2023

Figure 12. Seasonal average minimum temperature outlook for NSW issued on 02 November 2023

Official national outlook

The official national outlook was released by the Bureau of Meteorology on 2 November 2023.

The rainfall outlook for November to January shows that there is likely chance (60 to 80%) of below median rainfall for most of western, northern and southern Australia.

Maximum temperatures for November to January have a very likely chance (greater than 80%) of being warmer than average for most of Australia. Minimum temperatures for the November to January period have a likely to very likely (60% to 80%) chance of being warmer than average for most of Australia.

Forecast accuracy at this time of year has generally been moderate to high for most of Australia. The Bureau issues a new 3-month seasonal update weekly, each Thursday afternoon.

Global climate drivers

El Niño–Southern Oscillation (ENSO)

The Bureau of Meteorology’s El Niño-Southern Oscillation (ENSO) Outlook was released on 8 November 2023. The ENSO Outlook status is at El Niño.

Sea surface temperatures (SSTs) in the tropical Pacific Ocean continue to exceed El Niño thresholds. Atmospheric indicators over the Pacific continue to reflect El Niño. The Southern Oscillation Index (SOI) is negative. Models indicate that the El Niño is likely to persist into early autumn 2024.

Southern Oscillation Index

The 30-day Southern Oscillation Index (SOI; Figure 13) for the 30 days ending 03 November was -7.5. The 90-day SOI value (as of 22 October) was -10.0. Sustained negative values of the SOI below −7 typically indicate El Niño while sustained positive values above +7 typically indicate La Niña.

Figure 13. Latest 30-day moving SOI sourced from Australian Bureau of Meteorology on 9 November 2023

Sea surface temperatures (SST)

Monthly sea surface temperatures (SST) were warmer than average across most of the tropical Pacific Ocean (Figure 14). Warm SST anomalies persist along parts of the Australian coastline. Warm anomalies also remain in the southern Tasman Sea. Warm anomalies to the west of Australia increased in extent with waters warmer than 2 °C above average off parts of the north-west coast of Western Australia

The latest values of the three NINO indices in the tropical Pacific for the week ending 5 November  were: NINO3 +1.90 °C, NINO3.4 +1.64 °C, NINO4 +1.44 °C (sourced from the Bureau of Meteorology on 9 November 2023).

Persistent NINO3 or NINO3.4 values warmer than +0.8 °C are typical of El Niño, while persistent values cooler than −0.8 °C typically indicate La Niña.

Figure 14. Monthly sea surface temperature anomalies (Source: NOAA)

Sub-surface sea temperatures

The four-month sequence of equatorial Pacific sub-surface temperature anomalies (to 31 October 2023) shows warm anomalies across most of the Pacific basin for the top 100m in depth, except the far west (Figure 15). These warm anomalies reached more than 2.50C above average for the eastern Pacific.

Figure 15. Monthly sea sub-surface temperatures (Source: Australian Bureau of Meteorology)

Indian Ocean (IOD)

A positive Indian Ocean Dipole (IOD) is currently underway. The latest weekly value of the Indian Ocean Dipole (IOD) index to 5 November 2023 was +1.55°C. The weekly index values for this positive IOD event are the second highest since records for the Bureau SST dataset began in 2001.

All the international climate models surveyed by the Bureau of Meteorology suggest a positive IOD event is likely to continue into December. A positive IOD can suppress winter and spring rainfall over much of Australia, including NSW. When a positive IOD and El Niño occur together, their drying effect is typically stronger and more widespread across Australia.

Southern Ocean (Southern Annular Mode – SAM)

The Southern Annular Mode (SAM) index currently positive (as of 06 November).

The Southern Annular Mode (SAM) refers to the north-south shift of rain-bearing westerly winds and weather systems in the Southern Ocean compared to their usual position. This indicator can be quite volatile and generally influences weather conditions on 1 to 3 week timescales. A neutral SAM has little influence on Australian rainfall

Figure 16. Southern Annular Mode (SAM) Daily Index and Forecast Summary (Source: Australian Bureau of Meteorology on 6 November 2023)

CDI status for the regions

Figure 17 displays the CDI status for each individual Local Land Services (LLS) region to 31 October 2023. The following regional descriptions are based on data available until the end of October 2023.

Figure 17. Combined Drought Indicator status for each individual Local Land Services region – 31 October 2023

Murray and Riverina regions

Murray and Riverina regions production outlook continues to remain positive heading into summer.

  • The Riverina and Murray Local Land Services (LLS) regions remain in the Non-Drought category at the end of October (CDI, Figure 18).
  • October rainfall was near average to below average across most of the region. Higher than average rainfall was recorded in the southwest of the region.
  • The NDVI anomaly (Figure 19) shows that most of the Murray and Riverina regions were experiencing normal to higher than normal plant greenness levels. This is a likely a result of vegetation responding to recent rainfall events through October.
  • There has been an expansion in the area that is showing close to average levels of greenness between Hay and Jerilderie since the September Update.
  • Some of the extremely negative NDVI areas (dark brown patches) represent water or fallowed paddocks.

Drought indicators have seen a sharp decline in recent weeks consistent with reduced rainfall across the region.

  • The Drought History charts (Figure 20) show the individual response of the drought indicators for Hay, Temora, Finley, and Moulamein.
  • The indicators remain high at all locations however there has been a sharp decline in the individual drought indicators over the past month, with some areas in the east of the LLS regions approaching the Drought Affected category threshold. Producers continue to monitor conditions closely.
  • To access a Drought History chart for your Parish, visit the Seasonal Conditions Information Portal.

The Combined Drought Indicator (CDI) is a tool that monitors drought conditions across NSW. The drought categories are based on assessing the response of three drought indicators: soil water, plant growth and rainfall. The indicators track the data over the past 12 months and show how the indices are tracking compared to long-term averages. The information provided in the map is aggregated to a Parish level and provides a regional assessment of conditions. Variability within and between farms is possible and this may not be reflected in the CDI map.

Figure 18. Combined Drought Indicator for the Murray and Riverina regions

Figure 19. NDVI anomaly map for the Murray and Riverina LLS regions For an accessible explanation of this map contact the author seasonal.conditions@dpi.nsw.gov.au

Figure 20. Drought History charts for select sites in the Riverina (Hay, Temora) & Murray (Finley, Moulamein) LLS regions show the current and historical status of the three drought indicators: Rainfall Index, Soil Water Index, and Plant Growth Index

Western region

Western region producers are monitoring their local seasonal conditions and forecasts closely in line with their production systems.

  • The Combined Drought Indicator (CDI, Figure 21) shows that approximately 25% of the Western LLS region is currently in the Drought Affected category.
  • Conditions continue to decline and the extent of the region in drought has expanded since the September Update.
  • October rainfall was near average to below average across most of the region. Higher than average rainfall was recorded in the southeast of the region.
  • The seasonal NDVI anomaly data (Figure 22) shows that levels of plant greenness were variable across the region. The areas that have below average levels of greenness has expanded over the past month.
  • There are localised areas of below normal vegetation condition throughout the region. These may be indicative of short-term drying events (3-6 months) that are not evident in a 12 month indicator like the CDI. Some of the extremely negative NDVI areas (dark brown patches) represent water.

Drought indicators are declining in many areas  consistent with the onset of a drought event.

  • The Drought History charts (Figure 23) show the individual response of the drought indicators for Bourke, Ivanhoe, Wentworth, and Broken Hill.
  • The indicators remain high at Ivanhoe and Wentworth, however these locations are experiencing steady decline in all indicators.
  • Bourke has recently transitioned into the Drought Affected category and without substantial rainfall in the coming weeks, conditions will continue to decline.
  • The Broken Hill parish remains in the Non Drought category however there has been a rapid decline in all the indicators over the past month, indicative of significant drying event in the past 6 –9 months. Substantial rainfall is needed to ensure the region does not enter the Drought Affected category. Field reports indicate that producers assess their current field condition as ‘mild drought’.
  • To access a Drought History chart for your Parish, visit the Seasonal Conditions Information Portal.

The Combined Drought Indicator (CDI) is a tool that monitors drought conditions across NSW. The drought categories are based on assessing the response of three drought indicators: soil water, plant growth and rainfall. The indicators track the data over the past 12 months. This shows how the indices are tracking compared to the long-term averages. The information provided in the map is aggregated to a Parish level and provides a regional assessment of conditions. Variability within and between farms is possible and this may not be reflected in the CDI map.

Figure 21. Combined Drought Indicator for the Western LLS region

Figure 22. 3-month NDVI anomaly map for the Western region

Figure 23. Drought History charts for select sites in the Western LLS: Bourke, Ivanhoe, Wentworth and Broken Hill show the current and historical status of the three drought indicators: Rainfall Index, Soil Water Index, and Plant Growth Index

North West, Northern Tablelands and North Coast regions

The drought event continues to intensify, with producers focussing on short to medium term management strategies for their productions systems, especially livestock welfare, water and feed availability.

  • The Combined Drought Indicator (CDI, Figure 24) shows all three regions are in one of the drought categories at the end of October.
  • Conditions continue to decline and the extent of the region in the Drought and Intense Drought categories has expanded since the September Update.
  • October rainfall was near average to below average across most of the three regions. Higher than average rainfall was recorded on the north coast near Lismore and Port Macquarie.
  • The seasonal NDVI anomaly data (Figure 25) shows that levels of plant greenness were variable across the region. The areas that have below average levels of greenness has expanded over the past month and indicate low levels of ground cover and standing dry matter available for livestock. Some of the extremely negative NDVI areas (brown patches) represent water. The white patches represent missing data.
  • On ground reports suggest that some producers are continuing to provide supplementary or full hand feeding stock as part of their drought management strategies.
  • The NSW DPI continues to closely monitor conditions in these regions.

Drought indicators are in decline in all regions consistent with the continuation of a drought event.

  • The Drought History charts (Figure 26) show the individual response of the drought indicators for Tenterfield, Moree, Walgett, and Lismore.
  • There has been a continued, sharp decline in the indicators all locations.
  • Moree remains the Drought Affected category, however it is expected to transition into the Drought category in the coming weeks, and likely the Intense Drought category without substantial rainfall in the coming weeks.
  • Indicators have declined further at Lismore and the region has recently transitioned into the Intense Drought category.
  • To access a Drought History chart for your Parish, visit the Seasonal Conditions Information Portal.

The Combined Drought Indicator (CDI) is a tool that monitors drought conditions across NSW. The drought categories are based on assessing the response of three drought indicators: soil water, plant growth and rainfall. The indicators track the data over the past 12 months and shows how the indices are tracking compared to the long-term averages. The information provided in the map is aggregated to a Parish level and provides a regional assessment of conditions. Variability within and between farms is possible and this may not be reflected in the CDI map.

Figure 24. Combined Drought Indicator for the North West, Northern Tableland and North Coast regions

Figure 25. 3-month NDVI anomaly map for the North West, Northern Tableland and North Coast regions

Figure 26. Drought History charts for select sites in the Northern Tablelands (Tenterfield), North West (Moree & Walgett) and North Coast (Lismore) show the current and historical status of the three drought indicators: Rainfall Index, Soil Water Index, and Plant Growth Index

Central Tablelands, Central West, Hunter and Greater Sydney regions

Drought conditions continue to expand across the four Local Land Services regions. On ground reports show producers are implementing drought management strategies for their productions systems.  

  • The Combined Drought Indicator (CDI, Figure 27) shows that 100% of the Hunter and Greater Sydney LLS region, and approximately 85% of the Central West and 65% of the Central Tablelands are in one of the drought categories. At the time of writing this report 82% of the Central Tablelands LLS region was in one of the drought categories.
  • October rainfall was near average to below average across most of the four regions.
  • The seasonal NDVI anomaly data (Figure 28) shows that levels of plant greenness were variable across the region. The areas with below average levels of greenness has expanded over the past month and indicate low levels of ground cover and standing dry matter available for livestock. Some of the extremely negative NDVI areas (brown patches) represent water. The white patches represent missing data.
  • On ground reports suggest that some producers have commenced early weaning as part of their drought management strategy.
  • NSW DPI continues to closely monitor conditions in these regions.

Drought indicators continue to decline rapidly across the four regions.

  • The Drought History charts (Figure 29) show the individual response of the drought indicators for Cowra, Condobolin and Singleton.
  • There has been a further decline in the CDI indicators at Singleton with the region in Drought Affected category. Without substantial rainfall, the region is expected to transition into the Drought category over the coming weeks
  • Indicators at Condobolin has seen a rapid decline over the past few weeks and without substantial rainfall, the region is expected to transition into the Drought Affected category over the coming weeks.
  • To access a Drought History chart for your Parish, visit the Seasonal Conditions Information Portal.

The CDI is a tool that monitors drought conditions across NSW. The drought categories are based on assessing the response of three drought indicators: soil water, plant growth and rainfall. The indicators track the data over the past 12 months and show how the indices are tracking compared to the long-term averages. The information provided in the map is aggregated to a Parish level and provides a regional assessment of conditions. Variability within and between farms is possible and this may not be reflected in the CDI map.

Figure 27. Combined Drought Indicator for the Central Tablelands, Central West, Hunter and Greater Sydney regions

Figure 28. 3-month NDVI anomaly map for the Central Tablelands, Central West, Hunter and Greater Sydney regions

Figure 29. Drought History charts for select sites in the Central Tablelands (Cowra), Central West (Condobolin), and Hunter (Singleton and Scone) show the current and historical status of the three drought indicators: Rainfall Index, Soil Water Index, and Plant Growth Index

South East region

Drought conditions continue to intensify for parts of the South East region. On ground reports show producers are focussing on short to medium term strategies for their productions systems.  

  • The Combined Drought Indicator (CDI, Figure 30) shows approximately 60% of the region in one of the drought categories.
  • Conditions continue to decline and the extent of the region in drought has expanded since the September Update.
  • October rainfall was near average in the south and below average across the rest of the region.
  • The seasonal NDVI anomaly data (figure 31) shows that levels of plant greenness were variable across the region. The areas that have below average levels of greenness has expanded over the past month and indicate low levels of ground cover and standing dry matter available for livestock. Some of the extremely negative NDVI areas (brown patches) represent water. The white patches represent missing data.
  • The NSW DPI continues to closely monitor conditions in this region.

Drought indicators have continued to decline over the past month. The drought indicators are continuing to rapidly decline in parts of the coast and hinterland.

  • The Drought History charts (Figure 32) show the individual response of the drought indicators at Bega, Cooma and Goulburn.
  • There has been a rapid decline in the individual indicators at Cooma and Goulburn.
  • The Cooma parish has recently transitioned into the Drought Affected category.
  • Goulburn remains in the Non Drought category but indicators continue to decline and without substantial rainfall, the region is expected to transition into the Drought Affected category over the coming weeks.
  • There has been a continued decline in all indicators at Bega and has transitioned into the Intense Drought category in the past week.
  • Producers in these areas should monitor local conditions closely and on ground reports suggest that many producers are implementing drought management strategies in line with their production systems.
  • To access a Drought History chart for your Parish, visit the Seasonal Conditions Information Portal.

The Combined Drought Indicator (CDI) is a tool that monitors drought conditions across NSW. The drought categories are based on assessing the response of three drought indicators: soil water, plant growth and rainfall. The indicators track the data over the past 12 months and shows how the indices are tracking compared to the long-term averages. The information provided in the map is aggregated to a Parish level and provides a regional assessment of conditions. Variability within and between farms is possible and this may not be reflected in the CDI map.

Figure 30. Combined Drought Indicator for the South East region

Figure 31. 3-month NDVI anomaly map for the South East region

Figure 32. Drought History charts for Bega, Cooma and Goulburn in the South East LLS show the current and historical status of the three drought indicators: Rainfall Index, Soil Water Index, and Plant Growth Index

How does it work?

Figure 33. Description of the Combined Drought Indicator (CDI) framework

The Combined Drought Indicator is one source of information that informs policy and Government responses to changing seasonal conditions, including drought. The map provides a snapshot of conditions at a point in time and is not used to determine eligibility for drought assistance measures offered by the NSW Government.

Much of the information in the Seasonal Conditions Report is sourced from the NSW DPI Enhanced Drought Information System (EDIS)™. The EDIS system is subject to an intensive ground truthing process. For more information, visit the interactive website via droughthub.nsw.gov.au.

EDIS is an ongoing project aimed at improving the quality and timeliness of efforts to monitor conditions across the state. Key features of the system are:

  • It tracks drought by using four indicators; rainfall, soil water, plant growth, as well as tracing rainfall trends. Agronomic conditions have equal value to rainfall recorded at meteorological stations.
  • The Combined Drought Indicator (CDI) brings this information together and has been designed to characterise developing drought conditions. The key purpose for building the CDI was as a drought early warning system.
  • The rainfall, soil moisture and plant growth indicators in EDIS account for conditions over a 12-month window. This provides a compromise between a highly sensitive indicator (e.g. six months) and a less sensitive indicator (e.g. 24 months).
  • Climate and remote sensing data drive the information system at a high resolution, but the CDI is reported at a Parish level.
  • Because of its configuration and purpose, there will be differences to the indicator used in the National Drought Monitoring Framework (the Australian Rainfall Deficiency Analyser) which relies on rainfall alone.
  • The CDI has three drought categories that characterise NSW according to drought intensity as well as the main drivers of a drought event (meteorological, hydrological and agronomic). DPI considers areas Drought Affected to be experiencing a drought event.
  • The Drought Affected category encompasses a wide range of conditions from the very early stages of drought entry through to a drought event becoming intense. This enables the drought monitoring system to detect a drought event early. It is also possible to stay in the Drought Affected category for some period of time.

The way in which the indicators are combined to form the CDI is described in Table 1 below.

Table 1: Description of the Combined Drought Indicator framework

CDI Phase

Technical definition

Description - typical field conditions

Intense Drought

All three indicators (rainfall, soil water, plant growth) are below the 5th percentile

Ground cover is very low, soil moisture stores are exhausted and rainfall has been minimal over the past 6-12 months.

Drought

At least one indicator is below the 5th percentile

Conditions may be very dry, or agronomic production is tight (low soil moisture or plant growth). It is possible to be in Drought when there has been some modest growth, or a few falls of rain.

Drought Affected (intensifying)

At least one indicator is below the 30th percentile and the rainfall trend is negative over the past 90 days.

Conditions are deteriorating; production is beginning to get tighter. Ground cover may be modest, but growth is moderate to low for the time of year. When indicators are close to the Drought threshold drought conditions are severe.

Drought Affected (weakening)

At least one indicator is below the 30th percentile and the rainfall trend is positive over the past 90 days.

Production conditions are getting tighter, but there have been some falls of rain over the past month. It is rare to enter the Recovering phase from the Non-Drought category; Usually there is a quick (1-2 week) transition into Drought Affected or Drought. When indicators are close to the Drought threshold drought conditions are severe.

Recovering

All indicators are greater than the 30th percentile AND any indicator is less than the 50th percentile AND the previous category is Drought Affected.

Production is occurring but would be considered ‘below average’. Full production recovery may not have occurred if this area has experienced drought conditions over the past six months.

Non-drought

All indicators greater than the 50th percentile or all indicators are greater than the 30th percentile AND the previous category is Non-drought

Production is not limited by climatic conditions.

The NSW State Seasonal Update is provided each month by the NSW DPI Climate Branch.

Information used in this report was primarily sourced from the Australian National University, Australian Bureau of Meteorology, the US National Oceanic and Atmospheric Administration, the International Research Institute for Climate and Society (Columbia University), Geoscience Australia’s Digital Earth Australia Program, and NSW Department of Primary Industries.

Maps in this document contain data which is © Spatial Services – NSW Department of Finance, Services and Innovation (2023), Panorama Avenue, Bathurst 2795 and data which is © Commonwealth of Australia 2023, Australian Bureau of Meteorology, Melbourne, and © Australian National University. All rights reserved.

The seasonal outlooks presented in this report are obtained from the Australian Bureau of Meteorology and other sources (including World Meteorological Organisation Global Producing Centres). 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.

All climate and remote sensing input data is supplied to the Enhanced Drought Information System™ under the Australian Creative Commons Licence (CCY 4.0) and is made available by the Terrestrial Ecosystem Research Network.