NSW State Seasonal Update - February 2022

Prepared by NSW DPI

NSW overview

New South Wales continues to experience strong production conditions despite variable rainfall across the state this past month. Eastern NSW received above average rainfall whilst  the rest of the state has been average to below average for February. Most of NSW is currently in non-drought with the NSW DPI Combined Drought Indicator (CDI) showing 97% of NSW in the Non-Drought category at the end of February. At the end of February 2022, parts of eastern NSW are being impacted by severe flooding. The extent of damage to agricultural production in this region will become clearer over the coming weeks.

High soil moisture, average rainfall, and full water storages have helped to maintain ground cover and pasture availability. Although in many districts the nutritional value of pasture for livestock has declined over recent months. The productive seasonal conditions also create challenges for producers, such as weed and vertebrate pest management. There have been opportunities in many parts of the state to conserve fodder for future droughts.

The irrigated crop forecast for the 2021-22 season remains high due to high soil moisture levels and water availability in the state’s major irrigation storages.

Despite strong seasonal conditions overall, parts of Western NSW and the western Murray Local Land Services region continue to experience a slow, variable or delayed drought recovery. The agronomic indictors have recently improved in some regions, though consistent follow-up rain is needed to provide opportunities for longer-term drought recovery.

The latest Bureau of Meteorology (BoM) Seasonal Outlook indicates moderate to high chances of above median rainfall across NSW for the three months between March and May. The ENSO Outlook status is currently at La Niña. The Indian Ocean Dipole (IOD) is neutral and models indicate that the IOD will remain neutral in the coming months. Sea surface temperatures in the eastern tropical Pacific Ocean remain cooler than average. Warmer than average sea surface temperatures persist across the western Pacific.

The CDI and its individual rainfall, soil moisture and crop/pasture growth metrics are leading biophysical indices of drought. 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. To report local conditions, use DPI Farm Tracker https://www.dpi.nsw.gov.au/climate-and-emergencies/droughthub/cdi/edis-self-reporting.

Rainfall

The rainfall anomaly data shows the difference between total monthly rainfall and the long-term average monthly rainfall (1961-1990; Figure 2a). Above average to well above average rainfall has been recorded along the coast and in northern NSW for February. The highest rainfall anomalies were in the North Coast Local Land Service (LLS) region. Most of central, southern, and western NSW have received average to below average rainfall in February.

The higher rainfall totals have been in the far north-east of the North Coast where rainfall of more than 800mm has been recorded (Figure 2b). Areas of the Riverina, Murray, and Western LLS regions have received less than 10mm of rainfall. For the calendar year to date coastal NSW had received between 200mm and 1200mm. Rainfall west of the Great Dividing Range has totalled between 10mm and 200mm (Figure 2c). Year to date rainfall has been very much above average for the north east and south east of NSW.

Temperature

Eastern NSW experienced average to below average maximum temperatures for February, whilst parts of the central west and south west NSW experienced slightly above average maximum temperatures (Figure 3a). The average February maximum temperatures ranged from 18°C to 30°C in eastern NSW. Areas west of the Great Dividing Range had maximum temperatures above 30°C, and above 33°C for northern and western areas of NSW (Figure 3b).

Minimum temperatures were generally close to or below average across most of NSW in February (Figure 3c). The average February minimum temperatures were above 9°C in eastern NSW and above 15°C in the west (Figure 3d). Southern alpine regions experienced cooler temperatures generally above 6°C, whilst minimum temperatures in the Tablelands ranged from 9 to 15°C.

Normalised Difference Vegetation Index (NDVI) Anomaly

The seasonal Normalised Difference Vegetation Index (NDVI, Figure 4) indicates that plant greenness levels are close to, or above normal across most of NSW for the December to February period. Slightly lower than normal plant greenness remains evident across parts of the Western, the North West and Murray LLS regions.

NSW Farm Dam Survey

The NSW Farm Dam Survey indicates dam levels are generally greater than 40% of capacity across eastern areas of NSW and above 80% capacity in regions that have received higher rainfall totals (as of 17 February 2022; Figure 5). Areas of western, southern and some coastal regions of NSW have farm dam levels less than 20% of capacity.

Significant Events

At the end of February and early March 2022, parts of eastern NSW are being impacted by flooding. The extent of damage to agricultural production in this region will become clearer over the coming weeks.

Soil Water Index

The Soil Water Index (SWI, Figure 6) indicates the majority of NSW is currently in the average to above average categories. This is a result of the rainfall that has been received over the past several months. Parts of western and south-western NSW remain in the below average category and a small region in the far south west is in the extremely low category.

Plant Growth Index

The Plant Growth Index (PGI, Figure 7) indicates that the majority of NSW is in the average to above average categories at the end of February. Parts of south-western and western NSW reflect a similar pattern with the SWI and are in the below average category.

Rainfall Index

The Rainfall Index (RI, Figure 8) indicates that the majority of NSW is currently in the above average or extremely high categories. This reflects the distribution of average or above average rainfall accumulated over the last 12 months. There is a small area in south-western NSW which is currently in the below average RI category.

Drought Direction Index

The Drought Direction Index (DDI, Figure 9) tracks the 150-day trend of daily rainfall totals. The DDI indicates a strong wetting trend in northern and coastal areas of NSW. Strong drying trends have emerged in eastern NSW on the slopes and tablelands, and parts of western NSW. Both weak drying and weak wetting trends are emerging throughout central and western NSW. The drying trends are a result of extremely high rainfall recorded in Spring 2021, where recent conditions have been drier relative to this wet spring period. This weak to strong drying trend does not indicate the emergence of a drought in the regions.

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

CDI status for the regions

Figure 10 displays the CDI status for each individual Local Land Services (LLS) region to 28 February 2022. The following regional descriptions are based on data available until the end of February 2022.

Murray and Riverina regions

The Combined Drought Indicator (CDI, Figure 11) shows that conditions in the Riverina and Murray Local Land Services (LLS) regions have remained unchanged since the January Update. All of the Riverina and most of the Murray remain in the Non-Drought or Recovery categories. There is an area in the western Murray LLS region that remains in the Drought Affected category and further rain is required to support long term drought recovery in this area.

The seasonal NDVI anomaly data (Figure 12) shows that most of the Murray and Riverina regions were experiencing higher than normal plant greenness levels for the December to February period. Plant greenness levels remain lower than expected in some western areas of the Murray and central areas of the Riverina LLS regions. The impact of the 2019/2020 bush fires is still evident south of Tumut.

The time series charts (Figure 13) show the individual response of the drought indices for Hay, Finley, Temora and Moulamein. Temora and Finley remain steady with average to high soil water, plant growth and rainfall indices. Continued rainfall and average temperatures have allowed Hay to remain in the Non-Drought category however further rainfall is needed to maintain conditions. Further rainfall is required at Moulamein to maintain recent improvements in the region. To access a time series for your Parish, visit the Combined Drought Indicator website.

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.

Western region

The Combined Drought Indicator (CDI, Figure 14) shows that whilst drought conditions remain variable across the region, conditions have improved since the January Update. Parts of the Drought Affected areas between Menindee and Broken Hill have now transitioned into the Non-Drought or Recovery categories. Some areas of western NSW remain in the Drought Affected category. Further rainfall is needed to support long-term drought recovery for these regions. The DPI continues to closely monitor conditions in Western LLS.

The seasonal NDVI anomaly data (Figure 15) shows variability across the Western LLS region. Much of the region is experiencing near normal to higher than expected levels of plant greenness for the December to February period. Areas in the far west and south-west continue to have lower than normal plant greenness levels.

The time series charts (Figure 16) show the individual response of the drought indices for Bourke, Ivanhoe, Wentworth, and Broken Hill. Ivanhoe remains in the Non-Drought category with high soil water, plant growth and rainfall indices. Continued rainfall is required at Bourke and Broken Hill to maintain the Non-Drought status and improve the soil water and plant growth indices. Wentworth remains in the Drought Affected category and rainfall is required to improve conditions. NSW continues to monitor the Western LLS region closely. To access a time series for your Parish, visit the Combined Drought Indicator website.

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.

North West, Northern Tablelands and North Coast regions

The North West, Northern Tablelands and North Coast Local Land Service regions continue to experience strong conditions for production given rainfall received over the past year. The Combined Drought Indicator (CDI, Figure 17) shows that the LLS regions are in the Non-Drought category.

The North Coast experienced severe flooding given the high rainfall in February and an east coast low pressure system tracking across the region in early March 2022. At the time of writing this State Seasonal Update the flood status remained active in the region and communities were assessing damage. Flood risk warnings also remain in place.  The extent of damage to agricultural production in these regions will become clearer over the coming weeks.

The seasonal NDVI anomaly data (Figure 18) indicated near to above-normal greenness across most of the regions for the December to February period.

The time series charts (Figure 19) show the individual response of the drought indices for Moree, Walgett, Tenterfield and Lismore. The indicators remain high at all locations. To access a time series for your Parish, visit the Combined Drought Indicator website.

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.

Central Tablelands, Central West, Hunter and Greater Sydney regions

The Central West, Central Tablelands, Hunter and Greater Sydney Local Land Services (LLS) regions continue to experience non-drought conditions. Productive conditions have generally been maintained due to rainfall received over the past year. The Combined Drought Indicator (CDI; Figure 20) shows that the LLS regions are in the Non-Drought category at the end of February.

Parts of the Hunter and Greater Sydney experienced localised flooding in early March 2022. At the time of writing this State Seasonal Update the flood risk warnings remain active in the region. The extent of damage to agricultural production in these regions will become clearer over the coming weeks.

The seasonal NDVI anomaly data (Figure 21) shows near normal to high levels of plant greenness across most of the LLS regions for the December to February period.

The time series charts (Figure 22) show the individual response of the drought indices for Cowra, Condobolin and Singleton. The CDI indicators remain high at all locations. These regions currently remain well placed for productive conditions in the coming months. To access a time series for your Parish, visit the Combined Drought Indicator website.

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

The Combined Drought Indicator (CDI, Figure 23) shows that the South East Local Land Services region remains in the Non-Drought CDI category. Productive conditions have generally been maintained due to rainfall received over the past year. At the time of producing this Update, the South East region is being impacted by heavy rain and warnings of minor flooding. The extent of damage to agricultural production in these regions will become clearer over the coming weeks.

The seasonal NDVI anomaly data (Figure 24) showed near normal to high levels of plant greenness across most of the region for the December to February period. Some areas impacted by the 2019/20 bushfires continue to have lower than average plant greenness levels.

The time series charts (Figure 25) show the individual response of the drought indices at Bega, Goulburn and Cooma. The three regions remain in the Non-Drought category with high soil water, plant growth and rainfall indices. These regions currently remain well placed for productive conditions in the coming months. To access a time series for your Parish, visit the Combined Drought Indicator website.

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.

Official national outlook

The official national outlook was released by the Bureau of Meteorology (BoM) on 3 March 2022. Rainfall during March to May is likely to be above median for eastern and central Australia. The risk of flooding remains high for central and eastern Australia due to high soil moisture, high stream flows, and predicted above median rainfall.

Maximum temperatures are likely to be warmer than median for western, south-east, and northern Australia during the March to May period. Parts of coastal NSW are likely to be cooler than median. Minimum temperatures for March to May are likely to be above median across Australia.

The Bureau issues a new 3-month seasonal update weekly, each Thursday afternoon.

NSW outlook

NSW has a 50% to above 80% chance of receiving above median rainfall between March and May with the higher rainfalls predicted towards the coast, particularly in the south east (Figure 26).

The maximum temperature outlook (Figure 27) indicates a less than 20% to above 50% chance of warmer than median temperatures across central and eastern NSW. There is a 60% to 75% chance of above median maximum temperatures across western NSW and the far north-west of the state.

There is a 70% to above 80% chance of warmer than median overnight temperatures across the state (Figure 28).

Global climate drivers

El Niño–Southern Oscillation (ENSO)

The Bureau of Meteorology’s (BoM) El Niño-Southern Oscillation (ENSO) Outlook was released on 01 March 2022. The La Niña continues in the tropical Pacific Ocean. Although the La Niña is past its peak, it may still contribute to weather events as we move into the peak of the tropical cyclone season. Climate models suggest that neutral ENSO conditions will return in mid-autumn 2022. La Niña typically increases the chance of above median rainfall in NSW during spring and summer, with a weaker influence during autumn.

Southern Oscillation Index

The 30-day Southern Oscillation Index (SOI) for the 30 days ending 27 February was +9.6 (Figure 29). The 90-day SOI value was +8.6. 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)

Sea surface temperatures (SST) along the equator in the central-to-eastern tropical Pacific remain cooler than average. Weaker warmer than average SSTs persist for parts of the Maritime Continent, and have strengthened in the north east and north west of Australia (Figure 30).

The latest values of the three NINO indices in the tropical Pacific for the week ending 27 February were: NINO3 -0.8°C, NINO3.4 -0.7°C, NINO4 -0.3°C.

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.

Sea sub-surface temperatures

The four-month sequence of equatorial Pacific sub-surface temperature anomalies (to 28 February 2022) shows cool anomalies across the eastern equatorial Pacific Ocean. (Figure 31). Sub-surface anomalies were 1.5-3ºC cooler than average to a depth of 100m in the equatorial Pacific east of 110°W. In comparison to January, warm anomalies across parts of the central to western Pacific have weakened. Warm anomalies of more than 3ºC above average currently extend from 140°E and 180ºE, at depths between 100 m and 175 m.

Indian Ocean (IOD)

The Indian Ocean Dipole (IOD) remains neutral. All five international climate models surveyed by the Bureau of Meteorology indicate that the IOD will remain neutral in the coming months. This is consistent with the typical life cycle of an IOD event. IOD events are typically unable to form between December and April when the monsoon trough shifts south over the tropical Indian Ocean. The latest weekly value of the Indian Ocean Dipole (IOD) index to 27 February 2022 was −0.46 °C.

Southern Ocean (Southern Annular Mode – SAM)

The Southern Annular Mode (SAM) index is neutral (as of 1 March) and is expected to remain neutral over the next two to three weeks (Figure 32). A neutral SAM typically has very little influence on the climate in New South Wales.

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 the usual position. This indicator can be quite volatile and generally influences weather conditions on 1-3 week timescales. SAM forecasts are highly uncertain beyond 2-3 weeks.

How does it work?

Much of the information in the Seasonal Conditions Report is sourced from the NSW DPI Enhanced Drought Information System (EDIS) ™. The EDIS system is currently available in prototype form and is subject to an intensive ground truthing process. For more information, visit the interactive website via DroughtHub.

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 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 (2022), Panorama Avenue, Bathurst 2795 and data which is © Commonwealth of Australia 2022, Australian Bureau of Meteorology, Melbourne. 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.