When it rains it pours: Australia is facing a wetter than usual autumn as La Niña weather system hangs around after a soaked summer – and it’s bad news for the eastern states
- Australians preparing for a soaking with La Niña conditions not going anywhere
- Experts say wetter than average conditions will continue for eastern Australia
- Bushfire risks will still remain for parts of Western Australia and Queensland
- The risk of wide spread flooding is highest for eastern and northern Australia
Australians should brace themselves for more wet weather ahead as La Niña conditions continue well into the autumn.
The country has shivered through its coolest and wettest summer in five years but experts said there will be no sign of a reprieve in the coming months.
Bureau of Meteorology climatologist Dr Andrew Watkins said the atmospheric phenomenon will keep the rain falling in March and April – particularly on the eastern coast.
Australians should brace themselves for wet months ahead with La Nina conditions to continue well into the autumn months. Pictured: Man runs past Sydney Harbour Bridge 2020
Temperatures this summer have been the coolest since 2012 – only rising above average in Queensland and the west coast of Western Australia.
December was the third wettest December since national records began in 1900, said Dr Andrew Watkins, a senior climatologist from the Bureau of Meteorology.
And bad news for Sydneysiders, rain is expected to continue into Autumn.
‘Autumn rainfall is expected to be wetter than average across large Eastern parts of Australia particularly in March and April’, Dr Watkins said.
Above average rainfall is also expected in dry areas of Queensland, while the rest of Australia will enjoy generally normal levels of rainfall.
The official autumn bushfire outlook predicts most of the country can expect average fire conditions this autumn.
The autumn outlook suggests a high likelihood of exceeding rainfall on the east coast. Pictured: BOM outlook
Risk of wide spread flooding is highest for eastern and northern Australia. Pictured: Flooding of Daly River in the Northern Territory in 2018
Parts of coastal Queensland still have above average normal bush fire potential, with bush fire risks to also remain for parts of Western Australia this autumn.
South Western Australia is one of the few places with ‘above normal’ fire severity for December to February due to a rainfall deficit in the winter and spring.
Eastern Victoria and northern Queensland show below normal bush fire potential, largely due to a wetter landscape.
Parts of coastal Queensland still have above average normal bush fire potential, with bush fire risks to also remain for parts of Western Australia. Pictured: Fraser Island fire from Dec 2020
Autumn days are expected to be warmer than average across Northern Australia, Tasmania and far western parts of Western Australia but cooler in parts of New South Wales.
Above-average minimum temperatures will continue across most of the country, with the exception of central and western South Australia and south-eastern Western Australia.
Daytime temperatures are expected to be above average for the far north and south as well as the far west.
The rest of Australia will experience neutral temperatures, except a chance of below average maximum temperatures for inland New South Wales.
The risk of widespread flooding is highest for eastern and northern Australia, where soils and catchments are already wet and are likely to see above average rainfall.
WHAT IS THE EL NINO PHENOMENON IN THE PACIFIC OCEAN?
El Niño and La Niña are the warm and cool phases (respectively) of a recurring climate phenomenon across the tropical Pacific – the El Niño-Southern Oscillation, or ‘ENSO’ for short.
The pattern can shift back and forth irregularly every two to seven years, and each phase triggers predictable disruptions of temperature, winds and precipitation.
These changes disrupt air movement and affect global climate.
ENSO has three phases it can be:
- El Niño: A warming of the ocean surface, or above-average sea surface temperatures (SST), in the central and eastern tropical Pacific Ocean. Over Indonesia, rainfall becomes reduced while rainfall increases over the tropical Pacific Ocean. The low-level surface winds, which normally blow from east to west along the equator, instead weaken or, in some cases, start blowing the other direction from west to east.
- La Niña: A cooling of the ocean surface, or below-average sea surface temperatures (SST), in the central and eastern tropical Pacific Ocean. Over Indonesia, rainfall tends to increase while rainfall decreases over the central tropical Pacific Ocean. The normal easterly winds along the equator become even stronger.
- Neutral: Neither El Niño or La Niña. Often tropical Pacific SSTs are generally close to average.
Maps showing the most commonly experienced impacts related to El Niño (‘warm episode,’ top) and La Niña (‘cold episode,’ bottom) during the period December to February, when both phenomena tend to be at their strongest
Source: Climate.gov