Australia should prepare to flood this stormy season with the Meteorological Agency (Bom), which predicts there is a double chance of a La Niña forming.
La Niña events increase the chances of above-average rainfall in northern and eastern Australia during the spring and summer. Bom climatologist Tamika Tihema says the agency has predicted that there is a double chance that La Niña will form after updates to the current modeling.
“This does not guarantee that a La Niña will occur, but that there is about a 50% chance that La Niña will form. This means that about half of the climate models used by the agency indicate that a La Niña event is likely to develop, ”she says.
Tihema says the possibility of La Niña affecting severe weather, with greater-than-average rainfall forecast for the eastern two-thirds of the country for the rest of the year, has increased the risk of flooding.
“For many areas, including parts of eastern New South Wales, eastern Victoria, northern Tasmania and southwestern Australia and northern Australia, soil moisture is wetter than average,” she says.
“As this will mean more rain on wet soil, there is an increased risk of flooding in these areas.”
Tihema says the increased chance of La Niña is partly attributed to sea surface temperatures in the central tropical Pacific, which have cooled over the past two months.
“We are seeing changes in both observations and climate model prospects that indicate an increased chance for La Niña in the coming months,” she says.
“The chances of exceeding the median rain are greater than 70% for large parts of the eastern two thirds of the country in the rest of 2021.
“The chances of above median precipitation in the period November to January are around 60% or more for the eastern two thirds of Australia.”
NSW SES Commissioner Carlene York says this year’s storm season – which traditionally runs from October to March – is likely to bring similarities to last year, including extensive heavy rainfall and the risk of flooding.
“During the previous storm season, we experienced major flooding across the state,” York says.
“Not long ago, our volunteers responded to the great flood event that overwhelmed communities across Hawkesbury-Nepean, Hunter and the Mid-North Coast. This event alone saw us respond to more than 14,000 requests for assistance, including more than 1,000 flood rescues.
“It is incredibly important that communities are sure that they are ready. Storms can happen at any time. The more you can do now to prepare, the less likely you will need emergency assistance from our volunteers when these weather events hit. ”
York says Covid-safe practices had been implemented to respond to shutdowns and ongoing health measures.
The bill states that while El Niño-Southern Oscillation (ENSO) is a “naturally occurring” part of the climate system, climate change continues to have an impact on changing weather patterns. Australia has warmed by 1.44 degrees since records began in 1910.
Southern Australia has seen a decline in rainfall of between 10 and 20% during the cool season in recent decades, while rainfall in northern Australia in the wet season has increased since the 1990s, with shorter and heavier showers. has become more frequent.
“Research suggests that El Niño may cause heavier rainfall over the central and eastern tropical Pacific during global warming, and La Niña precipitation may be heavier in the western Pacific and over the South Pacific … but what these changes mean for Australia is unclear, “Tihema says.
‘Research also suggests that there may be an increase in the frequency of major El Niño and La Niña events. What the future holds for El Niño, La Niña and their impact is the subject of current research. ”