Australia’s peak season for severe weather and risk of tropical cyclones

BOM

Issued: October 9, 2023

The Bureau of Meteorology has released its long-range forecast to help the community prepare for Australia’s peak season for severe weather.

While severe weather can occur at any time of the year, October to April is the peak time for severe weather in Australia including heatwaves, bushfires, tropical cyclones, severe thunderstorms and floods.

The current climate drivers, long-range forecast and recent conditions indicate an increased risk of heatwaves and bushfires this year.

Different climate drivers are influencing the coming severe weather season compared to the previous 3 years with El Niño and positive Indian Ocean Dipole (IOD) events underway this year.

For the 2023–24 season, the Bureau is expecting the following conditions:

  • Heatwave – the forecast shows a high chance of unusually warm temperatures for most of Australia until at least February 2024.
  • Bushfire – there’s an increased risk for much of eastern and southern Australia due to reduced rainfall, high fuel loads and above average temperatures.
  • Tropical cyclones – while overall likely to be below average, at least one tropical cyclone crosses our coast each season.
  • Severe thunderstorms – a normal risk of severe thunderstorms with dry conditions forecast for late spring and early summer.
  • Flooding – normal risk for localised flooding when storms bring heavy rain and during the northern wet season.

Senior Meteorologist Sarah Scully said overall Australians can prepare for dry and warm conditions with an increased risk of heatwaves and bushfire weather this spring and summer.

“Daytime and night-time temperatures have an increased chance of being unusually warm for October to February. Warm nights after hot days means little relief from heat and can lead to heat stress,” Ms Scully said.

“There is always a risk of dangerous and destructive fires in Australia at this time of year. Grass growth due to above average rainfall in the past 2 to 3 years is contributing to an increased fire risk.”

The Bureau has also forecast that this season there will be an 80% chance of fewer than average tropical cyclones.

Australia’s most cyclone-prone area is the north-west coast between Broome and Exmouth. Northern Queensland and the Top End of the NT also get a high number of tropical cyclones.

“On average the first tropical cyclone crosses the Australian coast in late December. This can be later in El Niño years – possibly early to mid-January,” she said.

“During El Niño, the number of tropical cyclones in the Australian region is often below average.”

Ms Scully said the start of the Australian summer monsoon is typically later than average during El Nino and positive IOD years.

“The average date is the last week in December and this season it’s more likely to be in the first or second week of January,” she said.

“Severe thunderstorms are more common during the warmer months, particularly in northern New South Wales, southern Queensland, inland Western Australia and across the tropical north.”

“Thunderstorm asthma can be triggered by thunderstorms after high grass growth in southern Australia from October to December when pollen levels are highest,” she said.

While the long-range forecast shows conditions are likely to be drier than usual for large parts of Australia, there is still a risk of riverine and flash flooding where storms bring heavy rainfall.

You can reduce the impact of severe weather by taking time to get ready before it happens.

We provide regular forecasts and warnings to support the community.

Stay up to date with the Bureau’s warnings. Download the BOM Weather app and set up your warning notifications.

/Bureau of Meteorology Public Release. View in full here.