Australian Government Bureau of Meteorology

 
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Bureau Outlook shows more wet weather likely this summer

25/11/2021

Consistent with Tuesday’s La Niña declaration, the Bureau of Meteorology's Summer Outlook shows eastern Australia is likely to be wetter than average, with an increased risk of tropical cyclones, heavy rainfall and widespread flooding.

There are no strong swings to either wetter or drier conditions in South Australia, while parts of Western Australia are likely to see average to slightly above average rainfall.

The Bureau’s Head of Operational Climate Services, Dr Andrew Watkins said several climate drivers are likely to create continuing wet conditions for parts of eastern Australia this summer.

“Over winter and spring we saw a negative Indian Ocean Dipole, a pattern of ocean temperature patterns in the oceans to our west that was favourable to rainfall over Australia, and a dominant influence on our climate. While this event is approaching its end, warmer waters to the north-west of Australia may persist, and continue to increase the chance of rainfall.”

“The big driver looking at the months ahead is La Niña, which is now established in the Pacific Ocean for the second year in a row. La Niña describes a pattern of ocean temperatures that sees warmer waters in the western Pacific, which in turn drives increased atmospheric moisture and rainfall, including heavy rainfall, over Australia. This pattern is likely to continue through until at least the end of January.”

"December is likely to see our typical summer weather systems pushed further south than normal, meaning more humid air coming off the Tasman Sea, and into NSW and eastern Victoria.

Even though this will be a wetter summer for many, Dr Watkins said the outlook was an important reminder for the community to always be vigilant for the potential risks of severe weather.

“Spring has been wetter than normal and, as a result, soil moisture is high, water storages are full, and we've seen flooding in some areas. Any additional rain on our already wet landscape will increase the flood risk for eastern Australia this summer.”

Bushfire risk may not be as high this summer as in some recent years, but bushfires happen every summer in Australia and even short periods of hot and windy weather will raise the fire risk.

"This year we need to be extra careful about grass and crop fires, particularly across inland areas and in the southwest of the country where we have had good growth over winter and spring" Dr Watkins said.

Summer days are likely to be warmer than average across most of Australia, except in the south-east. Minimum temperatures are likely to be above average across most of the country, so we’re in for some warmer nights.

“The risk of heatwave is about average this year, and it’s important to remember that heatwaves are Australia's most deadly natural hazard. Warm nights after hot days in particular make heat stress a significant health risk,” Dr Watkins said.

La Nina also means we’re expecting an average to above average number of tropical cyclones and lows. We’ve already seen our first tropical cyclone of the season, roughly three weeks earlier than normal. The Australian region experiences an average of 9 to 11 tropical cyclones each year, with four typically crossing the coast. Even when cyclones remain well off-shore coastal impacts can still be felt.

For more information about the Summer Outlook, please visit our website.

Know your weather. Know your risk. Stay up to date with the latest weather warnings on the Bureau website.

[MEDIA RELEASE ENDS]

SUMMER OUTLOOK SUMMARY

National

Please find the Bureau’s Head of Operational Climate Services, Dr Andrew Watkins, speaking on camera about the Summer Outlook here. Please find videos of Dr Watkins speaking about individual states and regions below.

Rain and flood

  • Spring rainfall has been above to very much above average for large areas of the eastern States, from western Queensland into the Alice Springs District in the Northern Territory, and for parts of southern South Australia.
  • Overall, it is likely to be the wettest spring since 2016.
  • November has been particularly wet, nationally likely to be the wettest since 2011, and amongst the ten wettest Novembers on record for New South Wales and South Australia.
  • Large areas of mainland Australia have received more than their average November rainfall so far, and flood warnings have been issued for numerous rivers in Victoria, New South Wales, Queensland and the southern Northern Territory
  • The current La Niña is likely to bring wetter than average conditions for much of the east coast of Australia
  • With wet soils, full rivers and high storages, additional rainfall on the already wet landscape means there is increased risk of widespread flooding this summer.

Temperature

  • Spring is likely to be the coolest since 2016 for Australia as a whole.
  • Both daytime and night-time temperatures were above to very much above average for much of the northern tropics.
  • Days were cooler than average for much of New South Wales and north-eastern Victoria, and inland Western Australia and part of Central Australia. Nights were cooler than average for parts of the inland south-east and much of Western Australia.
  • The summer outlook indicates daytime temperatures are likely to be warmer than average for most of Australia, but cooler than average for eastern New South Wales and far eastern Victoria. Nights are likely to be warmer than average for most of Australia.

Bushfire

  • Above normal vegetation growth has resulted in increased fire potential in parts of Western Australia's coastal South West, the Gascoyne, and a region of the coastal Pilbara.
  • Fire risk is also higher than average for much of inland New South Wales.
  • Recent rainfall and the wetter than average summer outlook mean there is below average fire potential in many forested areas along and east of the Great Divide in New South Wales and eastern Victoria, however increased grass and crop growth over spring may dry out during summer, increasing the grassfire risk.
  • Even where bushfire risk may not be elevated this summer, it’s important to remember bushfires happen every summer in Australia and even short periods of hot and windy weather will raise the fire risk.

Tropical cyclones

  • With warm waters around northern Australia, and La Niña in the tropical Pacific Ocean, we are expecting an average to slightly above average number of tropical cyclones and tropical lows this season.
  • The Australian region experiences an average of 9 to 11 tropical cyclones each year, with four typically crossing the coast (though coastal impacts can be felt when tropical cyclones remain well offshore).
  • TC Paddy formed on the morning of 22 November, near Christmas Island, well to the west of the Australian mainland. This was the first TC of the 2021–22 season. It is typical for the first TC of the season to form just after mid-November in La Niña years. Paddy fell to tropical low strength on the morning of 24 November.

Queensland

Please find Dr Watkins speaking on camera about the Summer Outlook for Queensland, including for regions such as North Queensland, Wide Bay and Burnett, central Queensland and South East Queensland.

Rain and flood

  • Spring has been wetter than normal, wettest since 2017, with above average rain for most of Queensland except the north-east and Cape York Peninsula.
  • The Wide Bay-Burnett region in south-eastern Queensland also received above average rain, easing the long-term drought, after having missed out on La Niña-driven rains last summer. However, some long-term deficiencies remain.
  • As a result, stream flows are intermediate to high soil moisture is high outside of Cape York Peninsula, and most water storages are higher than or similar to this time last year.
  • The La Niña is likely to bring wetter than average conditions for much of east coast of Australia, with highest chance of above average rainfall in eastern Queensland.
  • This additional rain on the already wet landscape means there is increased risk of widespread flooding this summer.

Temperature and bushfire

  • The Queensland bushfire season is generally from July to November.
  • Summer daytime temperatures are likely to be warmer than normal for much of Queensland outside the Cape York Peninsula and the south-east border region.
  • Minimum temperatures are likely to be above average across most of the State, so we're in for some warmer nights.
  • Bushfire risk may not be as high this summer as in some years, but bushfires happen every summer in Australia and even short periods of hot and windy weather will raise the fire risk.

Tropical Cyclone

  • With warm waters around northern Australia, we are expecting an average to slightly above average number of tropical cyclones and tropical lows.
  • The Australian region experiences an average of 9 to 11 tropical cyclones each year, with four typically crossing the coast (though coastal impacts can be felt when tropical cyclones remain well offshore).
  • Typically, 4 tropical cyclones form in Qld waters each year, but only one crosses the coast.
  • Qld has only experienced multiple tropical cyclones cross the coast during La Nina events.

NSW/ACT

Please find Dr Watkins speaking on camera about the Summer Outlook for New South Wales, including for regions such as the Northern Rivers, Central Coast, Sydney and Illawarra, and Western NSW.

Rain and flood

  • Spring has been wetter than normal, and some regions have recorded more than three times their normal November monthly rainfall.
  • As a result, stream flows are intermediate to high, soil moisture is high across most of the State, most water storages are higher than at this time last year, and we've seen flooding in some areas.
  • The La Niña is likely to bring wetter than average conditions for much of the east coast of Australia.
  • This additional rain on the already wet landscape, means there is an increased risk of experiencing more widespread flooding than normal this summer.

Temperature and bushfire

  • Summer daytime temperatures are likely to be warmer than normal in western New South Wales and cooler than normal in the east
  • Minimum temperatures are likely to be above average across most of the State, so we're in for some warmer nights.
  • Wetter forecast and observed conditions means normal to below normal fire potential in many forested areas east of the great divide, however over inland areas, increased grass and crop growth over spring may see that dry out during summer, increasing the grassfire and crop fire risk.

Victoria

Please find Dr Watkins speaking on camera about the Summer Outlook for Victoria, including for regions such as the Gippsland and Mallee/Wimmera.

Rain and flood

  • Spring has been wetter than normal for most of Victoria, except in the west, which received below average rainfall
  • As a result, soil moisture is high across most of the State, particularly in the east, and most water storages are higher than at this time last year.
  • The La Niña is likely to bring wetter than average conditions for much of the east coast of Australia, including Victoria.
  • This additional rain on the already wet landscape, means there is an increased risk of more widespread flooding than normal this summer.

Temperature and bushfire

  • Summer daytime temperatures are likely to be warmer than normal in western Victoria and cooler than normal in the east
  • Minimum temperatures are likely to be above average across most of the State, so we could be in for some warmer nights.
  • Wetter forecast and observed conditions means normal to below normal fire potential in many forested areas in the east of the State, however increased grass and crop growth over spring may see that dry out during summer, increasing the grassfire risk.

Tasmania

Please find Dr Watkins speaking on camera about the Summer Outlook for Tasmania.

Rain and flood

  • Spring has been wetter than normal for most of Tasmania, except in the west, which received average rainfall.
  • As a result, soil moisture is high across the State, and most water storages are higher than at this time last year.
  • The La Niña is likely to bring wetter than average conditions for much of the eastern Australia, except the west coast of Tasmania, where rainfall is likely to be below average.
  • Additional rain on the already wet landscape, means there's an increased chance of more floods than normal this summer.

Temperature and bushfire

  • Summer daytime temperatures are likely to be warmer than normal for most of Tasmania, particularly in the north and west.
  • Minimum temperatures are likely to be well above average across the State, so we're in for some warmer nights.
  • Wetter forecast and observed conditions means normal to below normal fire potential in many forested areas, however increased grass and crop growth over spring may see that dry out during summer, increasing the grassfire risk.
  • Bushfire risk may not be as high this summer as in some years, but bushfires happen every summer in Australia and even short periods of hot and windy weather will raise the fire risk.

South Australia

Please find Dr Watkins speaking on camera about the Summer Outlook for South Australia, including for the Eyre Peninsula and Riverland.

Rain

  • Spring has been wetter than normal in western South Australia, dryer than normal in the far south-east, and has had average to above average rain elsewhere. Some regions across the west and south have received more than three times their normal November rainfall
  • As a result, stream flows are intermediate to high and soil moisture is high across much of the State, and most water storages are higher than at this time last year.
  • While the La Niña is likely to bring wetter than average conditions for much of the east coast of Australia, there are no strong swings to wetter or drier conditions across the State.

Temperature and bushfire

  • Summer daytime temperatures are likely to be warmer than normal for much of South Australia, except in the south-west.
  • Minimum temperatures are also likely to be above average across most of the State, except the south-west, so many of us are likely in for some warmer nights.
  • Bushfire risk may not be as high this summer as in some years, but bushfires happen every summer in Australia and even short periods of hot and windy weather will raise the fire risk especially in areas that have seen a lot of vegetation growth during spring.

Western Australia

Please find Dr Watkins speaking on camera about the Summer Outlook for Western Australia, including for regions such as the Kimberley, Pilbara/Gascoyne and South-West.

Rain

  • Spring has been wetter than normal for much of Western Australia except the parts of the north and north-west and parts of the south and south-west
  • Overall likely to be the wettest since 2018
  • As a result, stream flows are intermediate to high, soil moisture is high in most regions, and most water storages are higher than at this time last year.
  • There’s no strong swings towards wetter or drier conditions in Western Australia, even as La Niña is likely to bring wetter than average conditions to much of the east coast.
  • Summer is typically very dry in the southern half of the state

Temperature and bushfire

  • Summer daytime temperatures are likely to be warmer than normal for across most of Western Australia except the south coast, where temperatures will be closer to average.
  • Minimum temperatures are also likely to be above average across most of Western Australia except the south coast, so most of us are in for some warmer nights.
  • Bushfire risk is normal for much of the State, however above normal grass and crop growth has resulted in increased fire potential for parts of the Gascoyne and South West.
  • Remember, bushfires happen every summer in Australia and even short periods of hot and windy weather will raise the fire risk.

Tropical Cyclone

  • With warm waters around northern Australia, we are expecting an average to slightly above average number of tropical cyclones and tropical lows.
  • The Australian region experiences an average of 9 to 11 tropical cyclones each year, with four typically crossing the coast (though coastal impacts can be felt when tropical cyclones remain well offshore).
  • Typically around 7 tropical cyclones forms in waters off W.A every season
  • TC Paddy formed on the morning of 22 November, near Christmas Island, well to the west of the Australian mainland. This was the first TC of the 2021–22 season.
  • It is typical for the first TC of the season to form just after mid-November in La Niña years, but in early December in most other years.

Northern Territory

Please find Dr Watkins speaking on camera about the Summer Outlook for Northern Territory, including breakdowns for both Darwin and Alice Springs.

Rain

  • Spring has been wetter than normal, with above average rain for most of the Northern Territory except the far north.
  • As a result, stream flows are intermediate to high, soil moisture is high outside of the far north, and most water storages are higher than at this time last year.
  • The La Niña is likely to bring wetter than average conditions for much of the east coast of Australia, with the Northern Territory seeing no strong swings to wetter or drier than average conditions.
  • The monsoon typically arrives in Darwin about ten days earlier than normal during La Nina wet seasons, around 18 December.

Temperature and bushfire

  • Summer daytime temperatures are likely to be warmer than normal for across all of the Northern Territory.
  • Minimum temperatures are also likely to be above average across the Territory, so we're in for some warmer nights.
  • Fire risk continues in localised areas which have not received rainfall. Normal fire potential is expected across all regions for the summer period.

Tropical Cyclone

  • With warm waters around northern Australia, we are expecting an average to slightly above average number of tropical cyclones and tropical lows.
  • The Australian region experiences an average of 9 to 11 tropical cyclones each year, with four typically crossing the coast (though coastal impacts can be felt when tropical cyclones remain well offshore).