February rainfall generally low, deficiencies increase
February rainfall was below average for Australia as a whole, despite very heavy rainfall in large parts of northern Queensland, which resulted in flooding.
Below to very much rainfall was extensive, affecting most of Western Australia, South Australia, the Northern Territory, southeastern quarter of Queensland and inland south of the State, and the northeastern third of New South Wales and the far west of the State. Rainfall was near-average for much of southeastern Australia.
An active monsoon trough, and a slow-moving low pressure system produced extremely heavy rainfall in tropical Queensland from late January into early February, causing flooding on Queensland's tropical coast between Daintree and Mackay, and parts of the western Peninsula and Gulf coast (see Special Climate Statement An extended period of heavy rainfall and flooding in tropical Queensland).
While flooding was severe on parts of the coast around Townsville, and continued for multiple weeks in the Gulf Country and Northwest, rainfall has only alleviated rainfall deficiencies in areas concentrated around the Northern Territory border in northwestern Queensland and at the eastern edge (roughly around Longreach) of the area of deficiencies which extend across the southeastern quadrant of Queensland.
Elsewhere deficiencies have persisted or increased.
5-month rainfall deficiencies
Northern Australia receives the bulk of its rainfall between October and April (the northern wet season), so rainfall deficiencies during this period are particularly significant, and will not usually be removed before the following wet season. For the 2018–19 northern wet season so far, rainfall has been below average over most of the northern Territory, the northern half of Western Australia, and most of the southern half of Queensland.
Following low February rainfall outside of northern Queensland, deficiencies have increased across northern Western Australia, the Northern Territory, southeastern Queensland, and northern New South Wales. Deficiencies have decreased in northwestern Tasmania, but still persist across the west of the State.
Exceptional rainfall in much of northern Queensland has removed deficiencies in western Queensland.
Serious or severe rainfall deficiencies for the period starting October 2018 affect much of the coast of northern Western Australia, from Northwest Cape to the Kimberley; a large area in the central Northern Territory, and isolated pockets about the Top End coast; a large area in the southeastern quadrant of Queensland, extending into adjacent northern New South Wales; some areas of northeastern South Australia; across western Tasmania; and isolated pockets of southern Victoria in West Gippsland and on the west coast around Warrnambool.
11-month rainfall deficiencies
Deficiencies which emerged across southern and eastern Australia following a poor wet season (southern Australia receives the bulk of its rainfall between April and November) have persisted through a drier than average summer.
Compared to last month, deficiencies have most notably increased across the Northern Territory and the north of Western Australia, eastern South Australia, and northern New South Wales.
Exceptional rainfall in much of northern Queensland has removed deficiencies in much of western Queensland.
Serious or severe rainfall deficiencies are in place across eastern South Australia (except the extreme southeastern tip); across Gippsland in Victoria, and part of the Central District; much of western, northern, and central southern New South Wales; southern Queensland, extending north to around Longreach; much of the Northern Territory away from the southwest and the Top End, where only small pockets are affected; and across much of the north of Western Australia, as well as areas in the central Gascoyne, and much of the South Coast and Southeast Coastal districts.
23-month rainfall deficiencies
Exceptional rainfall in much of northern Queensland has reduced deficiencies in northwestern Queensland, but they persist along the border and in the Channel Country.
Deficiencies have increased across eastern Australia, along the western coast of Australia, and in the Northern Territory.
Serious or severe rainfall deficiencies persist across southern and central Queensland, except for the coastal southeast and most of the Wide Bay and Burnett District, and also for parts of the west of the State in the Channel Country; most of New South Wales, except the northeast coast and most southern regions; across eastern Victoria and the east of the Central District; areas of coastal eastern and northern Tasmania; much of the eastern half of South Australia away from the far southeast and far northeast; and areas of the central Northern Territory.
For the Murray-Darling Basin rainfall for this period was the second-lowest on record behind 1900–02, compared to all other 23-month periods ending in February since 1900.
In Western Australia deficiencies are in place along the coast from about Port Hedland to the South Coastal District.
Compared to January, relative lower-layer soil moisture (from 10 cm to 100 cm deep) has decreased across northeastern New South Wales and southeastern Queensland, parts of Western Australia in the south, west, and north, the north of the Northern Territory, and in parts of Central Australia.
Following flooding rains in the north of Queensland, lower-layer soil moisture has increased across much of the north and west of the State.
Soil moisture for February was below average for much of the west, south and north of Western Australia; most of the Northern Territory; most of South Australia except the northwest; the southeastern quadrant of Queensland and along the southern border; northeastern New South Wales, as well as parts of the west and east of the State; much of Victoria except parts of the northeast and northwest; and western Tasmania.
Soil moisture was above average for a large part of Queensland, covering most of southern half of Cape York Peninsula and across the base of the Peninsula from the Central Coast to the northwest, and extending into the Gulf Country and Central West districts, and the northwest of the Channel Country. Soil moisture was also above average for a pocket of the southeast of the Interior District in Western Australia.
- February rainfall below to very much below average for much of Australia
- Rainfall above average for parts of northern Queensland, from the northwest to the central coast, and parts of Cape York Peninsula
- Very heavy rainfall in northern Queensland reduced deficiencies in some areas of the west and adjacent Northern Territory, but for most of Australia deficiencies have generally increased
- Lower-level soil moisture below average for February across most of Australia; above average for large areas of northern and western Queensland
- Temperatures above average in most areas, adding to moisture stress
Product code: IDCKGD0AR0
Soil moisture details are reported when there are periods of significant rainfall deficits.
Soil moisture data is from the Bureau's Australian Water Resources Assessment Landscape (AWRA-L) model, developed through the Water Information Research and Development Alliance between the Bureau and CSIRO.
See: Australian Landscape Water Balance.
What is drought?
Drought is a prolonged, abnormally dry period when the amount of available water is insufficient to meet our normal use. Drought is not simply low rainfall; if it was, much of inland Australia would be in almost perpetual drought. Because people use water in so many different ways, there is no universal definition of drought. Meteorologists monitor the extent and severity of drought in terms of rainfall deficiencies. Agriculturalists rate the impact on primary industries, hydrologists compare ground water levels, and sociologists define it by social expectations and perceptions.
It is generally difficult to compare one drought to another, since each drought differs in the seasonality, location, spatial extent and duration of the associated rainfall deficiencies. Additionally, each drought is accompanied by varying temperatures and soil moisture deficits.
Rainfall averages, variability and trends
- Average rainfall: How much rain do you expect?
- Rainfall variability: How consistent is rainfall in your area?
- Rainfall history: Check tables, graphs and data from your local weather station.
- Rainfall trends: Has your rainfall changed?
Lowest on record - lowest since at least 1900 when the data analysed begin.
Severe deficiency - rainfalls in the lowest 5% of historical totals.
Serious deficiency - rainfalls in the lowest 10% of historical totals, but not in the lowest 5%.
Very much below average - rainfalls in the lowest 10% of historical totals.
Below average - rainfalls in the lowest 30% of historical totals, but not in the lowest 10%.
Average - rainfalls in the middle 40% of historical totals.
Above average - rainfalls in the highest 30% of historical totals, but not in the highest 10%.
Very much above average - rainfalls in the highest 10% of historical totals.
For the week to 26 March 2019, rainfall was recorded in parts of all States and Territories.
At the start of the week, surface troughs extended through western, northern, and eastern Australia, generating isolated showers and thunderstorms through inland Western Australia and along the east coast of New South Wales. The monsoon trough was located across far northern Australia.
In the first part of the week, severe tropical cyclone Trevor was situated on the monsoon trough, near Lockhart River on the eastern side of the Cape York Peninsula. Trevor made landfall just south of Lockhart River, and brought widespread heavy falls to the Cape York Peninsula and north tropical coast of Queensland; moderate falls were reported through parts of northern and central Queensland. Trevor tracked across the far north of the Cape York Peninsula, and generated heavy falls.
Thunderstorms developed over the east coast of New South Wales and southeast Queensland due to an active surface trough in the region, and produced moderate falls.
Meanwhile, tropical cyclone Veronica formed along the monsoon trough, off the northwest of Western Australia. The system rapidly intensified into a severe tropical cyclone, and approached Port Hedland on the Pilbara coast. Thunderstorms and heavy falls extended over a large area to the north and south of the system, with moderate to heavy falls recorded across much of the Pilbara coast and adjacent inland districts. A trough connected Veronica in the west and Trevor in the Gulf of Carpentaria, and produced an area of instability and isolated showers and storms over the Top End in the Northern Territory.
Mid mid-week, Trevor had re-intensified to a category 4 strength system over the Gulf of Carpentaria. Severe tropical cyclone Trevor tracked towards the Carpentaria coast of the Northern Territory, and made landfall south of Port McArthur, generating heavy falls. After Trevor made landfall, the system weakened to an ex-tropical cyclone, and continued to track south through the east of the Northern Territory, producing widespread moderate falls in eastern parts of the Northern Territory and western Queensland.
Veronica was lingering off the northwest coast in the last part of the week without making landfall, and continued to generate widespread moderate to locally heavy falls over the Pilbara.
In the south, showers associated with surface troughs brought light falls along the east coast and northern and eastern Tasmania at the start of the week, while a surface trough also brought light to moderate falls in the southwest of Western Australia. As the week progressed, a thick cloudband associated with the passage of a series of strong cold fronts extended across much of southeast Australia. Rain and thunderstorms generated moderate falls across Tasmania's Central Plateau and northeast, and northeast Victoria and eastern New South Wales in the middle of the week. In the last part of the week moderate falls were recorded in the Northeast Pastoral District of South Australia, through central New South Wales, and the inland slopes in northeast Victoria and southeastern New South Wales, and across western and northern Tasmania. Widespread light falls were reported over large parts of Victoria, Tasmania, and southern New South Wales.
Totals in excess of 300 mm were recorded on the tip of the Cape York Peninsula, between Cooktown and Cairns in the north tropical coast of Queensland, and on the Pilbara coast between Port Hedland and Karratha. The highest weekly total was 634 mm at Indee, around 60 km south of Port Hedland in northwest Western Australia. Several other locations in the coastal Pilbara, far north of Cape York Peninsula, and Queensland's north tropical coast also approached or exceeded 400 mm for the week. The second highest weekly total was 583 mm at Mossman South Alchera Drive, near port Douglas in Queensland.
Rainfall totals in excess of 200 mm were recorded in the Pilbara coast surrounding Port Hedland, parts of the southern Gulf Coast in the Northern Territory, and areas of far northern Queensland.
Rainfall totals in excess of 50 mm were recorded across much of the Pilbara; western Tasmania; parts of northeastern Victoria and elevated areas in southeast New South Wales; the western to central Top End and eastern parts of the Northern Territory; most of the Gulf Country; and northern and southwestern Queensland.
Rainfall totals between 10 mm and 50 mm were recorded in the Kimberley District in Western Australia and large parts of the western half of that State; parts in the north and east of the Northern Territory; the Northeast Pastoral and Flinders districts in South Australia; and in much of southern coastal, central, and northeastern Victoria. Similar totals were also recorded across most of Tasmania; across eastern New South Wales, and in a band through the middle of the State to the western border; and in much of Queensland except the inland southeast and parts of the Central Highlands and inland northwest.
Little or no rainfall was recorded along much of the west coast of Western Australia or in the Interior and Eucla districts, the western half of South Australia, the southwest of the Northern Territory, parts of inland southeastern Queensland, and pockets of northeast New South Wales and northwest Victoria.
Impact of recent rainfall on deficits
The Drought Statement, issued on 6 March 2019, discusses rainfall deficits over Australia for the 5-month (October 2018–February 2019), 11-month (April 2018– February 2019) and 23-month (April 2017– February 2019) periods. Rainfall deficit maps are available for these periods as well as for standard periods.
The maps below show the percentage of mean rainfall that has been received for the rainfall deficit period for the 5-month, 11-month and 23-month periods ending 26 March 2019.
Rainfall for the period 1 October 2018 to 26 March 2019
For the 5-month period, serious or severe rainfall deficiencies are in place across much of the northwest coast of northern Western Australia; a large area in the central Northern Territory, and isolated pockets about the Top End coast; a large area in the southeastern interior of Queensland, extending into adjacent northern New South Wales; small areas of northeastern South Australia; across western Tasmania; and isolated pockets of southern Victoria in West Gippsland and on the west coast around Warrnambool.
Rainfall in the past week has eased deficiencies slightly in central parts of the Northern Territory and in the Kimberley, and removed deficiencies along parts of the Pilbara coast near Port Hedland and Karratha. Deficiencies were also eased slightly over parts of southern inland Queensland.
Affected areas of western Tasmania have generally received less than 80% of average rainfall for the period. Areas in southern Queensland and northern New South Wales have generally received between 30% and 60% of average; areas in the Kimberley, western Tasmania, and southern Victoria generally received less than 50% of average; and areas in the northeast and west of the Pilbara and central Northern Territory generally received less than 40% of average.
0% and 60% of average, while affected areas in the Pilbara and central Northern Territory generally received less than 40%.
Rainfall for the period 1 April 2018 to 26 March 2019
Serious or severe rainfall deficiencies are in place at the 11-month period across eastern South Australia except the in the far southeast; across Gippsland in Victoria and part of the Central District; much of western, northern, and central southern New South Wales; most of southern Queensland, extending north to around Longreach; much of the Northern Territory away from the southwest and the Top End, where only small pockets are affected; and across much of the north of Western Australia, as well as areas in the central Gascoyne, and much of the South Coast and Southeast Coastal districts.
The rainfall in the last week eased deficiencies in parts of the Pilbara coast and northern Kimberley in Western Australia, and slightly eased deficiencies in the eastern Northern Territory, southwestern Queensland, northeastern South Australia, and western New South Wales.
Affected areas of southern coastal Western Australia and the northern Kimberley, southeastern South Australia, eastern Victoria, central to eastern parts of New South Wales, and east coast Queensland have generally received between 40% and 70% of average rainfall for the period. Affected areas in northwestern New South Wales, northeastern South Australia, and central parts of the Northern Territory have generally received 20% to 40% of average rainfall for the period. Following recent rainfall, a small area of the eastern central Northern Territory has received more than 50% of average for the time period.
Across central to southern Queensland rainfall has generally been between 50% and 30% of average for the period, and less than 30% in small areas. The eastern Pilbara and north of the Interior District in Western Australia has received similar totals for the period, though deficiencies have been removed in the region between Port Hedland and Karratha.
Rainfall for the period 1 April 2017 to 26 March 2019
Serious or severe rainfall deficiencies at the 23-month time scale are evident from the central to southern interior to and the southwest of Queensland, and also for parts of the far west of the State in the Channel Country; most of New South Wales, except the northeast coast and most southern regions; across eastern Victoria and the east of the Central District; areas of coastal eastern and northern Tasmania. Deficiencies are also in place across much of the eastern half of South Australia away from the far southeast and far northeast; areas of the central Northern Territory, and along the coast of Western Australia from about Port Hedland to the South Coastal District.
The rainfall in the last week eased deficiencies in parts of the Pilbara coast in Western Australia near Karratha and slightly eased deficiencies in a small area of the central Northern Territory, and some affected areas in southwest Queensland.
Totals in affected areas are generally between 30% and 70% of average for the period. About the coastal western Pilbara and the conjunction of Queensland, New South Wales and South Australia totals for the period have been less than 50% of average.
Product code: IDCKGRWAR0