Australia noticed a story of two climate extremes final month, with extraordinarily dry circumstances persevering with throughout southern elements of the nation as elements of japanese New South Wales recorded the wettest Might on file.
The low strain trough that developed off the coast of NSW on 18 Might and lingered for days, led to file excessive rainfall in quite a few areas all through the Hunter and mid-north coast.
A number of climate stations skilled each day downpours exceeding 200mm, with many breaking month-to-month and each day rainfall data for Might, in line with the Bureau of Meteorology’s local weather abstract.
Bellingen’s Promised Land climate station recorded 802mm of rain for the month, greater than twice its common. The NSW city, situated about midway between Sydney and Brisbane, additionally set a file for the very best each day rainfall for Might, with 337mm on 22 Might.
File each day totals for Might had been additionally set at Williamtown RAAF base (149mm on 23 Might) and Morisset (126mm on 19 Might) within the Hunter area.
Might is normally a dry time of yr for northern and central Australia. However a number of locations within the Kimberley and Northern Territory skilled heavy falls of 100mm or extra in 48 hours, in line with the BoM.
In the meantime the dry spell continued throughout southern Australia, with rainfall in Victoria and South Australia greater than 70% under common for the month. Victoria skilled its driest Might since 2005, in line with the BoM. It was additionally the state’s second warmest Might on file.
The persistent dry circumstances have contributed to a heightened winter bushfire threat for South Australia and Victoria.
Most temperatures in Might had been 1.08C above the 1961-1990 common, BoM knowledge confirmed, and minimal temperatures had been up 0.6C.
“If you look at the weather charts, we’re seeing a subtropical ridge sitting south of Australia close to the start of winter, and that’s normally a pattern that you would expect to see in summer,” stated climatologist Darren Ray, a researcher based mostly on the College of Adelaide.
South Australian agricultural areas had been experiencing “extreme to exceptional drought”, he stated, with some areas recording their lowest “standardised precipitation index” values – a measure of drought – for the previous 12 to 18 months, in data that dated again to 1880.
The moist and dry extremes had been a part of the identical larger-scale system, with excessive strain over southern Australia encouraging moisture streams off the east coast, stated affiliate prof Ailie Gallant, who researches drought and rainfall extremes at Monash College.
after publication promotion
“This is an unusual situation. A lot of farmers in particular are really feeling the pinch right now, and unfortunately, with these types of events, we don’t know when it’s going to end,” she stated. “The best we can do is look on the horizon for the kind of weather systems that will promote heavy rainfall.”
The contrasting circumstances – massive areas in drought whereas others skilled record-breaking rain – had been “quite unusual”, in line with Dr Kimberley Reid, an atmospheric scientist on the College of Melbourne.
Reid stated drought in Australia was normally because of the lack of heavy rainfall, not only a lower in common rain. “One to five days of rain [annually] can be the difference between a drought, and not a drought for southern parts of Australia.”
There had been a whole lot of “frustratingly settled weather” and “clear skies” in southern Australia, she stated.
Nationwide, autumn common temperatures had been 1.41C above the 1961-1990 common, the fourth highest on file, in line with the BoM. Victoria had its warmest ever autumn, New South Wales and Western Australia second-warmest, and South Australia its third-highest.
“One thing that is clear is that 2025 will likely be the one of the warmest years on record, and so will the next few years,” Reid stated. “If we continue to burn fossil fuels – whether we burn them here at home or export them elsewhere to be burnt overseas – we’re going to keep seeing temperature records fall year on year if we don’t change our behaviour.”
