Spring Outlook: wetter than average spring likely for most of Australia

27/08/2020

Please note: The Bureau's 2020 Spring Outlook is scheduled for release at 10am today (Thursday, 27 August). The official winter summaries will be released Tuesday, 1 September.

Download a video and audio interview with Bureau Manager of Climate Operations Dr Andrew Watkins discussing the spring outlook and preliminary information about winter: AUDIO/VIDEO

The Bureau of Meteorology has released its 2020 Spring Outlook, showing much of Australia has a high likelihood of above average rainfall in the coming months.

The Outlook also shows daytime temperatures are likely to be average to below average throughout southern Australia and warmer than average in the north.

Overnight temperatures are likely to be above average for the entire country, with the only exception being south-west Western Australia.

The Bureau’s Manager of Climate Operations Dr Andrew Watkins said the outlook was being largely driven by changes in sea surface temperatures in the tropical Pacific and Indian oceans.

"Most long-range forecasts analysed by the Bureau, including from our own climate model, are indicating a La Niña could develop in the spring, which typically results in above-average winter-spring rainfall for Australia, particularly across eastern, central and northern regions.

"A La Niña also typically brings cooler and cloudier days, more tropical cyclones, and an earlier onset of the first rains of the northern wet season."

Dr Watkins said spring was typically a time of year when outlook models had a higher reliability.

"At this time of year, we start to see some of our main climate drivers locking in, which gives more certainty about what our weather patterns will be like in the coming months.

"We’re starting to see that in the Pacific with a La Niña beginning to take shape, and we are also seeing some changes in the Indian Ocean, which may also boost the chance of rain during spring."

Dr Watkins said the recent winter period is likely to be one of the warmest on record, with above average temperatures particularly prevalent across Western Australia and Queensland.

He also said that while the start to winter was very dry, August was the first wetter-then-average August since 2016.

"Overall, winter was drier than average for every state except New South Wales. It was particularly wet in Gippsland in Victoria and the south coast of New South Wales.

"Earlier in the winter period, conditions were drier than normal, as rain bearing weather systems were being blocked by a belt of high-pressure systems sitting across the country."

FAST FACTS

NATIONAL

Spring outlook:

• Above average rainfall predicted for most of eastern Australia. This is due to the potential development of La Niña, as well as warmer ocean temperatures in the eastern Indian Ocean.
• Warmer conditions and above average temperatures are likely, especially in the north of Australia and the far south-east including Tasmania.

Preliminary winter summary:

• Likely to be one of the ten warmest winters on record.
• A likely drier than average winter overall, despite wetter than average in August in some areas.

NEW SOUTH WALES/ACT

Spring outlook:

• Greater than 80% chance of exceeding median rainfall for the majority of the state, particularly central and western NSW due to an increased likelihood of a La Niña forming.
• A slightly lower chance of exceeding median rainfall along the mid to north coast.
• Higher than average temperatures predicted.

Preliminary winter summary:

• Rainfall was above average in July and August with total rainfall above the long-term average and the wettest winter since 2016.
• Several complex coastal lows resulted in heavy rainfall events for the south coast.
• Mean maximum temperatures were likely above average along the coast, and close to average inland.

VICTORIA

Spring outlook:

• High chance of exceeding the median rainfall for central and northern Victoria due to increased likelihood of a La Niña forming.
• Higher than average temperatures predicted, especially at start of spring until mid-September.

Preliminary winter summary:

• Drier than average winter across most of the state except for Gippsland where several coastal lows bought heavy rainfall resulting in a likely wetter than average winter.
• Statewide rainfall likely to be 25% below the winter average, and lowest since 2006.
• Days were warmer than average in most of the eastern and south-central Victoria; nights were cooler than average in most of western Victoria, but warmer than average in Gippsland.

WESTERN AUSTRALIA

Spring outlook:

• High chance of exceeding median rainfall in far south-east of the state.
• Average to drier than average conditions likely across the remainder of the state.
• High chance of exceeding median maximum temperatures in the north east, with predicted higher than average temperatures across the state.

Preliminary winter summary:

• Winter is almost certain to be the warmest on record; there was a record winter maximum temperature.
• Rainfall below average for most of the state, likely to be amongst the ten driest winters on record.
• A wetter than average August is likely to lead to near average winter rainfall along south coast.

TASMANIA

Spring outlook:

• Increased likelihood of above average temperatures right across the state.
• Higher chance of above average rainfall in north and western parts of Tasmania.

Preliminary winter summary:

• Very dry winter in the north-west, likely to be one of the ten driest on record, however, above average rainfall around Hobart and likely to be wettest winter record for Mt Wellington.
• Likely warmer than average days in the west, with nights close to average across state overall
• Liawenee set a new Tasmanian record low temperature with –14.2°C on 7 August.

SOUTH AUSTRALIA

Spring outlook:

• Very likely to be wetter than average across the state during spring.
• Average to cooler than average days and warmer nights, due to increased cloud cover.

Preliminary winter summary:

• Likely average to below average statewide rainfall, but wetter than average August across the state’s north.
• Coldest August day on record (7 August), which was more than one degree below the previous coldest August day in 1947.

QUEENSLAND

Spring outlook:

• High chance of exceeding average rainfall across the state, particularly in south and eastern parts of the state due to the increased likelihood of a La Niña event.
• Above average temperatures are predicted for the north half of Queensland.

Preliminary winter summary:

• Statewide rainfall is likely to be more than a third below the long-term average.
• Rainfall was above average in the far south-west.
• Likely to be one of the ten warmest winters on average, with the mean minimum temperature and mean temperature both likely to be more than a degree above long-term average.

NORTHERN TERRITORY

Spring outlook:

• High chance of above average rainfall across the majority of the state, particularly in the south-east.
• High chance of exceeding median maximum temperatures across the state, except for the south-east.

Preliminary winter summary:

• Mean maximum temperatures were above average and likely to be one of the five warmest Augusts on record.
• Conditions of climate and vegetation generated conditions are favourable for above-average dry season fire weather for north of the Territory.