Draft:2023 Australian Winter

2023 Australian Winter
Mean temperature deciles for the 2023 winter in Australia, showcasing above average temperatures across the country during this period.
Seasonal boundaries
Meteorological winter	June 1 - August 31
Astronomical winter	June 22 - September 23
First event started	March 6
Last event concluded	July 27

The 2023 Australian Winter was the warmest on record, showing an average of 1.53°C above the 1961-1990 average. The winter began on June 22 at the winter solstice, and concluded with the September equinox on September 23. The meteorological winter began on June 1, and finished on September 23.

Seasonal forecasts

Temperature outlook (max)

Temperature outlook (min)

Precipitation outlook

On May 25, 2023, the Australian Bureau of Meteorology released their forecasts for the upcoming winter. The maximum and minimum temperatures were predicted to be very likely (>80% chance) to exceed the average recorded between 1981 and 2018.

The precipitation levels during this time were predicted to have between a 20 and 40% chance of exceeding the accepted median for most of the country, however far northern Queensland showed signs of having above average rainfall.

Due to the El Niño and positive IOD (Indian Ocean Dipole), snowfall was forecasted to be below average for the season in the Australian Alps. Based on previous snow measurements at Spencer's Creek, NSW dating back to 1954, the average snow season in Australia tended to peak at around 198cm, however the forecast predicted a drop in about 36cm.

Seasonal summary

Average precipitation deciles in Australia between June and August in winter.

Queensland experienced its warmest June on record, and in July, most of Tasmania and south-eastern Australia also saw their warmest July ever. In August, the national mean maximum temperature was the second highest on record, with daytime temperatures ranking in the top 10% of historical observations across most of the country. Precipitation levels in the country tended to be below average in costal city suburban areas, however well above average in north-central Australia. Overall, the year showed slightly above average precipitation at just over 1.6% above the mean.

Snowfall in the Australian Alps started off slow, and peaked at 131cms as of July 13th. This was the lowest reading since the 2006 season which had a peak of 85.1cms. These low levels of snow could be attributed to the below average levels of precipitation and abnormally high temperatures seen throughout the season. Because of this, all of the Australian ski resorts had to postpone their opening day. A series of cold fronts delivered in the later stages of June, most notably between 19th-20th getting 30-35cm, and June 22-27 delivering between 55-80cm of snow. On July 8th snowstorm passed through, dumping fresh powder. Poor conditions following this led to a period of low snowmaking and overall a below-average season with many runs on some mountains being shut for the remainder of the season. The season ended prematurely compared to previous years due to the conditions.

Events

March to June cold fronts

Between March 6 and 10, a series of cold fronts swept across south-eastern Australia, bringing gusty winds and reducing daily maximum temperatures by up to 10 °C below the 1961-1990 average. Thunderstorms caused rain and showers throughout most of Tasmania, Victoria, and south-western New South Wales. In western Tasmania, rainfall totals ranged between 50 and 100 mm, and snowfall was reported at Mount Mawson in southern Tasmania.

On May 5, a cold front swept through the south-eastern states, bringing gusty winds, isolated thunderstorms, and polar air. On May 7, Cooma Airport in New South Wales recorded its lowest ever maximum temperature for May at 2.7 °C. Alpine areas in south-east New South Wales and north-east Victoria received 10 to 20 cm of snow. Additionally, on May 7, heavy hail was reported in parts of the Australian Capital Territory and Victoria.

Multiple cold fronts swept across the southern part of the country, bringing storms, strong winds, high daily rainfall totals, and snow. In south-eastern South Australia, many locations recorded their highest daily rainfall totals for June in over 100 years during the 24 hours leading up to 9 am on June 23. Daily rainfall totals in the Adelaide Hills generally ranged from 50 to 80 mm, resulting in flash flooding across the area.

Unseasonable Rainfall and Temperature Drops in Northern Australia

From the last 10 days of June until early July, an upper atmosphere trough pulled in tropical moisture from the Indian Ocean, northwest of the continent, bringing unseasonable rainfall to large parts of northern Australia. Typically dry at this time of year, these regions usually receive winter totals of less than 50 mm. During this period, daily rainfall totals ranged from 10 to 70 mm. Many stations with over 30 years of records reported their highest daily rainfall for June or July. The cloudy skies and rainfall also caused daily maximum temperatures to drop more than 10 °C below the 1961-1990 average in parts of northern Western Australia, most of the Northern Territory, and parts of western Queensland. Many stations recorded their lowest daily maximum temperature for July on the 1st and 2nd.

Severe weather cold front

On July 7 and 8, a strong cold front and deep low-pressure system struck south-east Australia, bringing damaging winds, widespread rainfall, below-average temperatures, hazardous surf, and snow in elevated areas. Alpine regions in Victoria, Tasmania, and New South Wales recorded more than 20 mm of snowfall. Daily rainfall totals exceeding 40 mm were observed at many stations across western and central Tasmania, as well as northern and eastern Victoria, by 9 am on July 8 and 9. Minor to moderate flood warnings were issued for catchments in north-east Victoria and north-west Tasmania.

Settled and dry conditions in July

Throughout July, frequent high-pressure systems brought settled and dry conditions to most of Australia. Clear skies and light winds led to low daily minimum temperatures across the southern and eastern parts of the country. Many stations in southern Queensland, eastern New South Wales, south-eastern South Australia, and Victoria recorded their lowest July minimum temperatures on record. Glen-Innes Airport in New South Wales set a new record with a minimum temperature of -10.8 °C on July 20, marking Australia's lowest temperature in 2023 and the coldest recorded outside the south-east alpine regions since 2019. Additionally, Canberra experienced 12 consecutive days of sub-zero night-time temperatures from July 16 to 27, a streak not seen since 1994.

See also

• Winter storm
• Weather of 2023