Weekly Australian Climate, Water and Agricultural Update, 22 February 2024

For the week ending 21 February 2024, a tropical low (07U) embedded into a monsoon trough developed over the Top End of the Northern Territory at the beginning of the week and strengthened into a category 1 Tropical Cyclone Lincoln. It made a landfall as it moved eastwards across the Top End, along the monsoon trough reaching the Gulf of Carpentaria, and brought heavy rainfall to much of the Gulf coast and parts of northern Queensland during the week. Onshore winds brought showers to eastern parts of the country. A high-pressure system kept much of the remainder of the country dry.

Across cropping regions, rainfall totals of up to 100 millimetres were recorded across parts of Queensland and up to 50 millimetres in northern and central New South Wales. These falls will continue to support the ongoing growth and lift the yield potential of summer crops. Additionally, these falls will help maintain soil moisture levels to support pasture growth and build reserves ahead of the upcoming winter cropping season. By contrast, Western Australia, South Australia, and Victoria and southern New South Wales remained dry, with declining levels of soil moisture.

Rainfall for the week ending 21 February 2024

Category 2 Tropical Cyclone and generate heavy rainfall in Western Australia’s Kimberley region earlier in the week and as it moves southward. South-western parts of Western Australia are also likely to benefit from the heavy rainfall, after being dry for several months. Showers and storms are expected in the tropics, extending to coastal east New South Wales.

Across cropping regions, rainfall totals up to 50 millimetres are forecast for Queensland and up to 25 millimetres in northern New South Wales. Western Australia, after being dry for several weeks, is expected to receive up to 100 millimetres of rainfall. If realised, these falls will continue to benefit soil moisture levels for pasture growth and support the growth of long season and later sown summer crops in Queensland and New South Wales. With the harvest of early planted summer crop now underway, wet weather over the next 8-days is likely to result in some harvest delays. While Western Australia will have some relief from this rain, more is required to prepare the sub-soil with sufficient moisture for the winter crops.

Little to no rainfall is expected across remaining cropping regions.

Total forecast rainfall for the period 22 February to 29 February 2024

The Bureau of Meteorology’s latest rainfall outlook for March 2024 indicates that rainfall is likely (60 to 80% chance) to be below median across much of western New South Wales, Queensland, Victoria, South Australia, Tasmania, the Northern Territory and northern Western Australia. Equal chances of below or above median rainfall is likely elsewhere.

The Bureau of Meteorology’s climate model suggests that for March 2024, there is a 75% chance of rainfall totals being over 25 millimetres across coastal east and northern Australia, as well as in western Tasmania and southern Victoria. Rainfall totals in excess of 100 millimetres are expected northern Queensland and Northern Territory.

Across cropping regions, there is at least a 75% chance of rainfall totals up to 25 millimetres in parts of New South Wales, Queensland, and southern Western Australia. March rainfall totals are expected to be below 10 millimetres for the remaining cropping regions.

If realised these forecast rainfall totals for March will provide some useful follow-up falls for dryland summer crop production as well as pasture growth across eastern and northern Australia. Dry conditions elsewhere will see a decline in soil moisture levels, particularly in Western Australia which has remained dry for several months, generating some concerns ahead of the upcoming winter cropping season. In contrast, relatively dry conditions across much of northern New South Wales and southern Queensland are likely to provide unimpeded access for the harvesting of early planted summer crops.

Rainfall totals that have a 75% chance of occurring in March 2024

The 2023 El Niño continues to weaken, and the Indian Ocean Dipole has returned to a neutral state. The rainfall outlook for March to May 2024 suggests that there is least a 50% chance of exceeding median rainfall across southern parts of Western Australia and in scattered areas in the southern and eastern Australia. Below median rainfall is likely across most of northern Australia, South Australia, Victoria and Tasmania.

Across cropping regions, 50% chance of exceeding median rainfall is likely in many growing regions.

Chance of exceeding the median rainfall March to May 2024

The outlook for March to May 2024 suggests there is at least a 75% chance of rainfall totals above 25 millimetres across much of Australia. The main exceptions being large areas of the interior and western coast where below 25 millimetres of rainfall are expected. Rainfall totals in excess of 200 millimetres are likely across tropical northern Australia, along Australia’s eastern coastline and western Tasmania during this period.

Across cropping regions, there is a 75% chance of receiving between 25 and 100 millimetres.

If realised, these falls will likely be sufficient to support autumn pasture growth across eastern and northern Australia and growth late planted summer crops. These falls are also likely to be sufficient to support the early planting of winter crops across those areas of eastern Australia that have benefited from above average summer rainfall and an associated boost to soil moisture profiles.

Rainfall totals that have a 75% chance of occurring March to May 2024