NSW State Seasonal Update - December 2023

Prepared by NSW DPI

NSW overview

Drought conditions are easing and much of NSW is in the early stage of recovery

• The NSW DPI Combined Drought Indicator (CDI; Figure 1) shows that 63% of NSW is in one of the three drought categories at the end of December.
• Most of this area is in the Drought Affected category with positive trends in drought indicators at or pointing towards recovery.
• Late November and December rainfall eased drought conditions for large areas of NSW, however parts of the Hunter, North and South Coast are still managing the impacts of a longer-term drought event.
• Easing of conditions is positive for landholders but the decision-making environment remains difficult for many NSW farmers.
• Conditions over the last 6-8 weeks have shifted farm management into an early recovery phase but concern about low sub soil moisture remains. This means that there is heightened risk that the recent improvement may not be sustained, further rainfall is critical in aiding a sustained longer-term drought recovery.

Current Conditions

• Recent rainfall has provided further relief from drought conditions in areas like the North Coast, South East, central NSW and the Hunter.
• The follow up rain has slowed or reversed the drought onset and intensification that had been occurring across the state.
• Widespread late spring and early summer rainfall lifted pasture production in most regions providing enough on ground feed to ease supplementary feeding programs, although feed quality remains a key management factor. Follow up rainfall over the coming months is critical in these regions for a sustained recovery from drought.
• Very hot temperatures were experienced throughout December, with higher evaporation rates impacting soil water values.

Seasonal Climate Outlook and Climate Drivers Update – January to March 2024

The outlook is for very warm conditions across NSW and an improved chance of above median rainfall for much of NSW in the January to March period.

• The rainfall forecast is variable for NSW, indicating a 55 – 65% chance of above median rainfall for much of NSW. Coastal areas in the north and much of far western NSW have a 45 – 55% chance of above median rainfall for this outlook period.
• The ENSO Outlook status is at El Niño and the Southern Oscillation Index is negative.
• The Indian Ocean Dipole (IOD) is currently positive but continues to weaken.
• 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 .

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

Variable rainfall during December

• Rainfall was variable across NSW during December (Figure 2a), with low totals recorded across the central region of western NSW.
• Large areas of NSW received 50mm to 100mm of rainfall.
• Significant rain fell in parts of NSW over the last week of December 2023
  • There was in excess of 200mm in the southeast including flooding rain on the south coast of NSW.
  • High rainfall was also recoded in parts of the North Coast and Northern Tablelands, with over 100mm recorded and localised flooding in some areas.
  • High intensity events have also been reported in isolated parts of NSW with flash flooding occurring.

Higher rainfall for much of NSW relative to long term records

• The December rainfall percentile map (Figure 2b) ranks the total rainfall for December 2023 compared to long term records from 1981-2020.
• December 2023 rainfall was in the top 80^th percentile of the historical record for parts of NSW. Some areas of the state had falls in above the 90^th percentile.
• Parts of the Hunter, Northern Tablelands, North Coast and Western LLS regions had lower rain totals in December 2023 relative to long term expectations, with falls in the 0-40^th percentile range.

Calendar year to date rainfall is average to below average for many areas.

• For the calendar year to date, eastern NSW has received between 600mm to 1000mm of rainfall (Figure2c).
• Areas around the southern alpine region, and an isolated areas on the North Coast have received more than 1000mm.
• West of the Great Dividing Range has generally received rainfall between 100mm and 600mm.
• Year to date rainfall has been average to very much below average for most of NSW.

Temperature

Higher than average maximum temperatures for most of NSW

• In December, the average maximum temperatures ranged from 15°C in the southern alpine region to above 36°C in the northwest of NSW (Figure 3a).
• Above average maximum temperatures were experienced across most of NSW in December (Figure 3b). Maximum temperatures were generally between 0°C and 3°C above average, with many areas experiencing extended periods of hot days.

Near average minimum temperatures for most of NSW

• Minimum temperatures were generally between 6°C and 21°C for most of NSW (Figure 3c). The warmest temperatures (above 21°C) were in the far northwest of the state.
• Minimum temperature anomalies were generally between 0°C and 2°C above average for most of NSW during December (Figure 3d).

Normalised Difference Vegetation Index (NDVI) Anomaly

The seasonal NDVI anomaly at 22 December indicates large parts of north-west, central and coastal NSW have lower than average vegetation condition.

• The seasonal Normalised Difference Vegetation Index anomaly (NDVI) indicates that plant greenness levels are variable across NSW (Figure 4).
• Many areas had above normal plant greenness levels, particularly in the west and south of the state.
• Areas of below average plant greenness have declined across the Central West, Hunter, North Coast and Central Tablelands Local Land Services areas.
• Areas of below average plant greenness have continued across the North West, and Northern Tablelands Local Land Services areas.
• On ground reports support this data, with low to very low ground cover being reported.
• The influence of recent rainfall on NDVI values at the end of December has not been included in this assessment.
• Some of the extremely negative NDVI areas (brown patches) are water bodies.

Decision support 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 slightly improved since the November update (Figure 5a).
• Higher farm dam levels are present across many parts of central, central north and southern NSW.
• Dam levels have improved along the NSW coast and hinterland.
• Large areas of Western NSW have dam levels below 40% capacity.
• The influence of recent rainfall on farm dam levels in the second half of December has not been included in this assessment.
• The farm dam assessment was not possible for some parts of NSW in December due to missing data.

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 5b) show producers in several regions are reporting they are managing mild to severe drought conditions in December.

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.

Significant weather events

Rainfall

• Severe thunderstorms were recorded for parts of NSW during December.
• These storms resulted in localised flash flooding, and damaging hail for regions such as the Central Tablelands, Central West, Greater Sydney and the Hunter.

Individual drought indicators

The individual indicators are being presented at a much finer resolution that in previous State Seasonal Updates. The maps now display the individual indicators at a 1km² gridded resolution. This allows readers to explore the indicator values (percentile scale 0-100) at a much higher level of detail.

The colour scale for each map transitions to a grey scale at the 30^th percentile. The 30^th percentile is one of the critical thresholds that DPI uses to monitor drought intensity (the threshold for Drought Affected). The grey scale also shows the 5^th percentile used to delineate Drought and IntenseDrought.

The Soil Water, Plant Growth and Rainfall indicators are all calculated by taking the mean of daily values over the last 12 months and ranking them relative to a 40-year baseline period. This configuration is used to detect moderate to severe drought events with a multiple season duration. The indicators track large changes and are not overtly sensitive to day-to-day or recent conditions over the past month conditions, so lag physical conditions in the field at the time of observation.

Soil Water Index

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

• Despite widespread rain, there is below the 30^th percentile SWI values for most of central, northern, and eastern NSW. Parts of western NSW also have below average SWI values (Figure 6).
• There has been a slight improvement in the SWI during December for parts of the South East, Central Tablelands and Hunter regions due to recent rainfall events.
• Areas of southern and western NSW continue to have near average to above average (50^th-80^th percentile range) root zone SWI values.
• Substantial rainfall in many areas is needed to trigger a substantial improvement in the SWI.

Plant Growth Index

Plant Growth Index values remain stable.

• The Plant Growth Index shows a moderate improvement since the November Update in parts of the Central West, Central Tablelands and South East (Figure 7).
• The Plant Growth Index shows that conditions are variable across NSW and display a similar pattern to the SWI values.
• There is below the 30^th percentile PGI values for most of central, northern and north eastern NSW.
• Substantial follow up rainfall over the coming weeks and conditions that aid plant growth is needed to trigger a substantial improvement in the PGI.

Rainfall Index

Rainfall Index values remain variable.

• The Rainfall Index (RI) is variable across the state (Figure 8).
• Most of central, northern and eastern NSW have RI values between the 5^th and 30^th percentile range.
• Recent rainfall has resulted in the improvement in the RI values across some parts of NSW. However further rainfall is needed to maintain or improve conditions.

Drought Direction Index

Drying trend continues for most of NSW.

• The Drought Direction Index (DDI) tracks the 150-day (5 months) trend of the Rainfall Index.
• Most of NSW is showing either a weak or strong drying trend due to below average rainfall over the past few months (Figure 9).
• This indicator continues to reflect the extremely dry rainfall pattern experienced in NSW during Winter 2023, with recent rainfall not being at a level to reverse the declining DDI.
• Shorter term (30-60 day) positive trends in the drought indices are evident at many locations (refer to the Regional Breakdown section for examples).
• Areas in the North Coast, Hunter and South East have seen a transition back to the Weak Drying Trend since the November update.
• This trend, combined with the decline in the individual drought indicators reflects the continuation of a major drought in these regions over recent months.

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

NSW outlook January to March 2024

(issued 4 January 2024)

Above median rainfall outlook for most of NSW

• The seasonal rainfall outlook indicates that there is moderate chance (between 55% to 65%) of above median rainfall for most of NSW during the January to March period (Figure 10).
• Coastal areas in the north and much of far western NSW have a 45 – 55% chance of above median rainfall for this outlook period.

Warm to hot conditions to continue for much of NSW. 

• The maximum temperature outlook indicates a 55% to above 80% chance of exceeding median daytime temperatures across NSW during the forecast period (Figure 11).
• There is an above 80% chance of warmer than median overnight temperatures across all of NSW during the forecast period (Figure 12).

Prospect of unstable weather to continue.

• There is continued risk of unstable weather across NSW in January and early February of 2024.
• The BoM outlook model indicates there is double the chance of January 2024 rainfall being in the top 20^th percentile for most of NSW.
• This is driven by a number of factors including warmer land surface temperatures, other climate drivers like the Southern Annular Mode (SAM), individual weather systems and warm local sea surface temperatures.
• It is important to continue to check medium range (2 week) and short range (3-1 day) weather forecasts.

Official national outlook

The official national outlook was released by the Bureau of Meteorology on 4 January 2024.

• The rainfall outlook for January to March shows that there is a 20% to 40% chance of above median rainfall for most of western and northern Australia. Large parts of inland Australia have a near equal chance of above or below median rainfall.
• Maximum temperatures for December to February have a very likely chance (greater than 80%) of being warmer than average for most of Australia.
• Minimum temperatures for the December to February 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 9 January 2024.
• The El Niño event continues, with indications it has likely peaked.
• Sea surface temperatures (SSTs) in the tropical Pacific Ocean continue to exceed El Niño thresholds.
• Models indicate that the El Niño is likely to persist into early autumn 2024.

Southern Oscillation Index

The 30-day Southern Oscillation Index (SOI) for the 30 days ending 7 January 2024 was -1.5. The 90-day SOI value was -5.3. Sustained negative values of the SOI below −7 typically indicate El Niño while sustained positive values above +7 typically indicate La Niña.

Sea surface temperatures (SST)

Monthly sea surface temperatures (SST) were warmer than average across the central and eastern tropical Pacific Ocean. Warm SST anomalies persist along parts of the Australian coastline, particularly the southeast and Tasmania. Warm anomalies also remain in the southern Tasman Sea.

The latest values of the three NINO indices in the tropical Pacific for the week ending 7 January were: NINO3 +1.63 °C, NINO3.4 +1.59 °C, NINO4 +1.30 °C (sourced from the Bureau of Meteorology on 9 January 2024).

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.

Sub-surface sea temperatures

The four-month sequence of equatorial Pacific sub-surface temperature anomalies (to December 2023) shows warm anomalies across most of the Pacific basin for the top 100m in depth. Cooler anomalies are present below the surface in the western Pacific basin. (Figure 15). These warm anomalies reached more than 3.0⁰C above average for the central and eastern Pacific.

Indian Ocean (IOD)

A positive Indian Ocean Dipole (IOD) continues but is rapidly weakening.

• The latest weekly value of the Indian Ocean Dipole (IOD) index to 7 January 2024 was +0.45°C.
• The international climate models surveyed by the Bureau of Meteorology suggest a positive IOD event is likely to continue to ease over the coming weeks, returning to neutral in January.
• Sea surface temperatures (SSTs) for the week ending 7 January 2024 were warmer than average across much of the western half of the tropical Indian Ocean, with warm anomalies extending in a band south-eastward to waters south of Australia.

Southern Ocean (Southern Annular Mode – SAM)

The Southern Annular Mode (SAM) index currently positive (as of 7 January).

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. During summer a positive SAM increases the chance of above average rainfall for parts of eastern NSW. This indicator can be quite volatile and generally influences weather conditions on 1-to-3-week timescales.

CDI status for the regions

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

Murray and Riverina regions

Murray region production outlook continues to remain positive.

• Most of the Murray and Riverina Local Land Services (LLS) region remains in the Non-Drought category at the end of December. Parts of both regions are currently in the Recovery category.
• Recent rainfall has help maintain productive conditions across the regions.
• Further rainfall is needed to ensure long term recovery from drought conditions that persist in parts of the Riverina LLS region.
• The seasonal NDVI anomaly data shows that levels of plant greenness were variable across the region. Most areas continue to experience normal to higher than normal plant greenness levels.
• Some of the extremely negative NDVI areas (brown patches) represent water. The influence of recent rainfall on NDVI values at the end of December has not been included in this assessment.

Drought indicators have responded to rainfall over recent months.

• The Drought History charts show the individual response of the drought indicators for Finley, Moulamein, Hay and Temora.
• The indicators have positive trends over the past 6-8 weeks at all locations due to high rainfall since mid November 2023.
• Producers continue to monitor conditions closely in conjunction with forecasts and outlooks.
• 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

Western region

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

• Conditions remain complex in the Wester LLS region. While the extent of the region in the Recovery category has increase since the November Update, parts in the far west transitioned from Non-Drought into the Drought Affected category.
• The Combined Drought Indicator (CDI) shows that approximately 50% of the Western LLS region remains in the Drought Affected category.
• November rainfall was variable, with much of the central region in the bottom 50% of the historical rainfall record. Higher than average rainfall was recorded in the northwest and southeast.
• Further rainfall is needed to aid any improvement in conditions across the region.
• The seasonal NDVI anomaly data shows that levels of plant greenness were variable across the region. Most areas continue to experience normal to higher than normal plant greenness levels. Areas with below average levels of greenness 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 influence of recent rainfall on NDVI values at the end of November has not been included in this assessment.

Drought indicators remain variable.

• The Drought History charts show the individual response of the drought indicators for Bourke, Ivanhoe, Wentworth, and Broken Hill.
• The indicators remain strong at Ivanhoe and Wentworth, in response to recent rainfall.
• Bourke has seen the indicators remain steady over the past month and remains in the Drought Affected category. Follow up rainfall in the coming weeks will be needed to trigger an improvement in conditions.
• The Broken Hill parish has transitioned back into the Drought Affected category, after being in the Recovery category. This area received below average rainfall during December and highlights the importance of sustained rainfall to aid longer term recovery from drought.
• Producers continue to monitor conditions closely in conjunction with forecasts and outlooks.
• 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

North West, Northern Tablelands and North Coast regions

Producers are continuing to focus on short to medium term management strategies for their productions systems.

• Drought event continues for the Northern Tablelands and North Coast.  Drought Conditions have eased slightly in the North West.
• The Combined Drought Indicator (CDI) shows all regions remain in one of the drought categories at the end of December.
• Recent rainfall has provided some relief from drought conditions and has slowed the drought intensification that has been occurring.
• Further rainfall is needed to ensure longer term improvement in conditions.
• The seasonal NDVI anomaly data shows that levels of plant greenness were variable across the region. Most areas continue to experience normal to higher than normal plant greenness levels.
• Some of the extremely negative NDVI areas (brown patches) represent water. The influence of recent rainfall on NDVI values at the end of December has not been included in this assessment.

Drought indicators remain low across the regions.

• The Drought History charts show the individual response of the drought indicators for Tenterfield, Moree, Walgett, and Lismore.
• There has been a positive trend in the indicators at all locations due to recent rainfall.
• Follow up rainfall over the coming weeks will be needed to trigger substantial improvement in conditions.
• 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

Central Tablelands, Central West, Hunter and Greater Sydney regions

Drought conditions continue to impact the regions

• The Combined Drought Indicator (CDI) shows most of these regions being in the Drought Affected category at the end of December.
• Recent rainfall has helped ease drought conditions, particularly in the south, however further rainfall in the coming weeks is needed to see the improvement in conditions continue across the regions.
• The seasonal NDVI anomaly data shows that levels of plant greenness were variable across all regions. Most areas continue to experience normal to higher than normal plant greenness levels. Areas with below average levels of greenness 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 influence of recent rainfall on NDVI values at the end of December has not been included in this assessment.

Drought indicators remain low in some regions, but have responded to recent rainfall.

• The Drought History chart show the individual response of the drought indicators for Cowra, Condobolin and Singleton.
• There has been an improvement in the drought indicators at all locations due to recent rainfall.
• The Rainfall Index is extremely high at Condobolin (at the 70^th percentile) as a result of isolated high intensity rainfall events recorded in the district. The agronomic (Soil Water and Plant Growth) remain low (near the 30^th percentile) with concerns that the effectiveness of the high intensity rainfall for production has been negligible.
• Further rainfall in the coming weeks is needed at all locations to trigger long term improvement in conditions.
• 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.

South East region

Drought conditions continue for parts of the South East region.  

• The Combined Drought Indicator (CDI) shows approximately 45% of the region in one of the drought categories.
• December rainfall was above average across the region, with significant rainfall occurring in parts of the region.
• This rainfall has provided some short-term relief to drought conditions and placed a large area of the LLS region in the Recovery category. For other areas it has reduced the intensity of drought, which have been managing drought conditions for many months.
• Continued rainfall is needed to help maintain conditions and ensure this is not a ‘false recovery’.
• The seasonal NDVI anomaly data shows that levels of plant greenness were variable across the region. Most areas continue to experience normal to higher than normal plant greenness levels. Areas with below average levels of greenness 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 influence of recent rainfall on NDVI values at the end of November has not been included in this assessment.
• The NSW DPI continues to closely monitor conditions in this region.

Drought indicators are variable across the region.

• The Drought History charts show the individual response of the drought indicators at Bega, Cooma and Goulburn.
• There continues to be an increase in the rainfall indicator at all locations due to the significant rainfall event that impacted the South Coast LLS region in December.
• Significant high intensity rainfall events have been recorded in the Bega region since November 2023, with the Rainfall Index now above the 50^th percentile level.
• The effectiveness of these rainfall events remains questionable, with stored soil moisture and pasture growth remaining low. The SWI and PGI remain below the 5^th percentile, keeping the location in the ‘Drought’ category.
• 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

How does it work?

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

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 (2024), 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.