BOM releases Drought Statement

Rainfall deficiencies since August 2023. Picture: BUREAU OF METEOROLOGY

The Bureau of Meteorology released a Drought Statement on Friday 5 April.

For Australia as a whole, the area-averaged rainfall total for March was 86.1 per cent above the 1961–1990 average, the third-wettest March on record since the national dataset began in 1900.

Overall, Western Australia had its fourth-wettest March on record and the Northern Territory its second-wettest March on record.

Rainfall was below average to very much below average (in the lowest 10 per cent for March since 1900) for Tasmania, most of Victoria, south-eastern South Australia, south-western Western Australia and parts of eastern New South Wales and central eastern Queensland.

March rainfall was the lowest on record for Victoria’s South West and Central districts.

Victoria had its seventh-driest March on record, with area-average rainfall 78.0 per cent below average and the driest March since 1986. For Tasmania, it was the driest March since 2005.

Mean maximum temperatures were above average to very much above average (in the highest 10 per cent for March since 1910) for Tasmania, Victoria, most of New South Wales and South Australia and parts of Western Australia and Queensland, with potentially increased evapotranspiration.

The long-range forecast released on 4 April indicated that for April to June, below median rainfall is likely to very likely (60 per cent to 80 per cent chance) to be below median for most of Australia.

Much of the east has about an equal chance of above or below median rainfall for April to June.

However, the likelihood of unusually low rainfall is below 50 per cent for all areas except the north-west.

Large areas of eastern Queensland, eastern and southern New South Wales, most of Victoria and Tasmania have about an equal chance of above and below median rainfall.

The chances of unusually low rainfall for April to June is below 50 per cent for all areas except parts of northern Australia.

Unusually low rainfall is defined as the driest 20 per cent of April to June periods from 1981 to 2018.

Maximum and minimum temperatures are likely to be above median except for parts of northern Australia.

The State of the Climate 2022 reported a long-term shift towards drier conditions across the south-west and south-east of Australia, particularly during the cool season months of April to October.

This is due to a combination of natural variability on decadal timescales and changes in large-scale circulation caused by an increase in greenhouse gas emissions.

Since the 1990s, in the absence of strong ‘wet’ drivers, cool season (April to October) rainfall in southern Australia has generally been lower than average.