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ABC News
3 days ago
- Climate
- ABC News
Eastern Australia faces another round of rain and snow as La Niña watch declared
Any hope of a premature end to winter is fading fast. In fact, this weekend will bring some of the coldest weather of the season, as a two-pronged pulse of polar air sweeps well north. After wintry precipitation this weekend across south-east states, including small hail and snow, further heavy rain will then develop along the New South Wales coast from Monday where this August is quickly becoming one of the wettest on record. The prospects of cool and wet weather lingering into spring is also rising for central and eastern Australia — just weeks after a negative Indian Ocean Dipole (IOD) formed, the National Oceanic and Atmospheric Administration (NOAA) has now declared a La Niña watch for the coming months. Twelve months ago, Australia's capitals were baking in unseasonable summer-like temperatures, including monthly highs of 33 degrees Celsius in Brisbane and 30C in Sydney, and 25C in Adelaide. Since 1910, August 2024 was nationally the warmest on record, following the third warmest in 2023. However, there will be no repeat of late winter warmth this year. A cold front swept onto the southern coastline on Friday, introducing polar air from the Southern Ocean, and with a second front trailing on Sunday, south-east states can expect an extended spell of temperatures as much as five below average. For today, isolated to scattered showers will impact southern South Australia, much of Victoria, and parts of NSW and Tasmania. The presence of a sub-Antarctic air mass will also lead to pockets of small hail and snow to low levels, although a lack of moisture will limit falls in non-alpine regions to just a centimetre or two. Saturday's lowest snow levels： So where could snowfalls arrive today? Dozens of non-alpine towns along the ranges may see a dusting, including on the higher hills around Trentham and Mount Macedon in Victoria, along with Bombala, Nimmitabel, Cooma, Jindabyne and Adaminaby in southern NSW. A few flakes are also possible this afternoon and tonight on the higher NSW Central Ranges and the Barrington Tops. The second pulse of polar air on Sunday will take a more western path over SA and western Victoria, and bring another round of showers and small hail. The trajectory of the coldest air over SA could lead to a rare light snowfall in the state, most likely on the higher Mount Lofty Ranges and southern Flinders Ranges. For Adelaide, Sunday is likely to be the coldest August day in five years with a maximum struggling to only 13C. Snow could then redevelop along the NSW ranges from Monday as the polar air tracks east, possibly including another snowfall on the Northern Tablelands, and the first settling snow of the year around the Blue Mountains. While the east coast will be spared a third consecutive weekend washout, as the polar air tracks east it will combine with moist onshore winds off the Tasman Sea to generate another week of rain. Model guidance on the amount of rain and location of the heaviest falls is currently variable, however the general consensus is between about 50 and 100 millimetres from about Brisbane to the Illawarra, although for now, heavy rain extending north of the NSW border is somewhat uncertain. For Sydney, where this August has already been the wettest in 27 years, another 100mm would make it the fourth wettest August since records began in 1859. The notable increase in recent rain across parts of Australia is partly the result of a wet phase of the Indian Ocean forming this winter, called a negative IOD. Once formed an IOD event normally lasts until December, but spring rain from this year's episode could be enhanced by the formation of a corresponding La Niña in the Pacific Ocean. The Bureau Of Meteorology no longer issues watches or alerts for climate drivers, however a watch was declared by NOAA this week after surveying a range of modelling through the coming months. "Based on this guidance and recent changes in the tropical Pacific, the forecast team narrowly favours La Niña thresholds being reached in three overlapping, three-month seasons," it stated in their monthly diagnostic report. However, even if La Niña thresholds are met this year, the event is looking short and weak, meaning in isolation the episode is unlikely to cause widespread flooding across Australia. But while La Niña's influence might remain minor, when combined with the wet signal from the Indian Ocean along with warm local waters surrounding Australia, the scales are still strongly tipped to indicate frequent rain this spring.
France 24
04-07-2025
- Climate
- France 24
Record cold grips Argentina, Chile and Uruguay
The three South American countries have all recorded sharply below-zero temperatures as the polar air originated from Antarctica and swept across the region. In Argentina, at least nine homeless people have died from the cold this winter, according to NGO Proyecto 7. The capital Buenos Aires recorded its lowest temperature since 1991 at -1.9 degrees Celcius (28.6 Fahrenheit) on Wednesday, while the coastal city of Miramar saw snow for the first time in 34 years. Further south, the town of Maquinchao recorded -18C on Tuesday. Electricity demand caused cuts across Buenos Aires, leaving thousands without power for over 24 hours in some areas. The government suspended gas supplies to industries and petrol stations Wednesday to ensure household supplies, and removed price controls on gas cylinders Thursday. Desert snow Uruguay declared a nationwide "red alert" after six people died, allowing President Yamandu Orsi's government to forcibly move homeless people to shelters. Montevideo recorded its lowest maximum temperature since 1967 at 5.8C on June 30, according to meteorologist Mario Bidegain. Chile also activated homeless shelter plans during the coldest days. The city of Chillan, 400 kilometers (250 miles) south of Santiago, hit -9.3C, according to the Chilean Meteorological Directorate. "What happened this week in Chile and the Southern Cone in general is a cold wave caused by an escape of a polar air mass from Antarctica," climatologist Raul Cordero from the University of Santiago told AFP. Snow even fell in parts of the Atacama Desert, the world's driest, for the first time in a decade. "It is not so common for these cold air masses to extend so far north, so we cannot rule out that this is also caused by climate change," meteorologist Arnaldo Zuniga told AFP. The region expects relief in the coming days, with Buenos Aires reaching 12C on Thursday, Montevideo 14C and Santiago 24.7C. "I was quite surprised by the change from cold to hot -- the change was very drastic," student Dafne Naranjo, 18, said in Santiago. Climatologist Cordero said heatwaves have become more frequent than cold spells in recent years. "The frequency of heatwaves has tripled, whether in summer or winter, not only in the Southern Cone but throughout the world," he said. © 2025 AFP
ABC News
05-06-2025
- Climate
- ABC News
Australia's snowiest weather in three years ahead for long weekend
South-east Australia will collectively shiver this long weekend as a mass of polar air from sub-Antarctic waters brings several days of showers, highland snow and well-below-average temperatures. The cold snap has the potential to bring the heaviest rain in one to two years across southern South Australia and south-west Victoria, a blessing for farmers who are desperate for relief from a record dry 16 months. The wintry storm is also likely to produce Australia's most widespread snow in years — ideal timing for alpine resorts for the opening of the ski season. The past two winters have been very lean snow-wise across Australia — both in terms of the ski season and non-alpine falls. And while winter 2025 is likely to be warmer than normal in general, the frigid air surging north will reduce speed once it reaches Australia, leading to a prolonged polar outbreak from Saturday, including potentially the most widespread snowfalls since 2022. Across the alpine regions, snow will fall above between about 800 and 1,200 metres for at least four days, comfortably below the elevation of our ski slopes, which sit mostly at a height between 1,400 to 2,000m. Modelling is confident the Saturday-Sunday period will drop around 40 to 60 centimetres across the major resorts, which in most years would equate to one of the best dumps of the season. Further snow will fall across the Alps from Monday; however, it's currently unclear whether the back half of the event will bring only a few centimetres each day or further moderate falls. For non-alpine regions, the prospect of snowfalls down to 800 metres raises the potential for a winter wonderland in numerous towns along the Great Dividing Range. In terms of extent, Victoria's snowiest day should be Sunday, followed by NSW on Monday when a dusting is likely on both the southern and central ranges, including around Oberon, Orange and the Blue Mountains. There's even the slight possibility of a quick flurry of snow in the hills around Canberra on Monday, and a few flakes may reach the northern NSW ranges on Tuesday. The Barrington Tops region of the Upper Hunter will also receive snow — falling on multiple days from Sunday onwards due to its high elevation above 1,500m. While major winter storms are more common from late June to August, it was only three years ago that a series of early June fronts brought similarly cold conditions and snow. On that occasion, well over one metre fell on the higher Alps in less than two weeks, so while this event is notable, it's far from record-breaking. For our capitals, temperatures will remain well above June records despite plummeting as much as 4 degrees Celsius below average, including the coldest maximums of: Sunday Adelaide 13C — coldest day since July 2024 (12.5C) Melbourne 12C — coldest day since September 2024 (10.8C) Monday Canberra 9C — coldest day since July 2024 (8.5C) Sydney 16C — was colder on June 4th (14.1C) Tuesday Brisbane 20C — was colder on May 30th (18.9C) The coldest air will bypass Tasmania, resulting in Hobart's maximums of around 14C being slightly above the June average. The presence of sub-Antarctic air well into the mid-latitudes will cause a low-pressure system to form and then track east through Bass Strait this weekend. Low-pressure systems bring rain, and thankfully for farmers, the system's slow movement will supply at least four days of showery weather. However, even before the low develops, a cold front will spread showers east through SA, Tasmania, and Victoria today with an average fall of 1 to 10 millimetres to whet the appetite ahead of the main event. As the low forms on Saturday the intensity of precipitation will increase, although totals will be highly dependent on location. Since winds spin clockwise around a low in the Southern Hemisphere, areas exposed to a westerly will see the heaviest falls on the mainland, including the SA coast and ranges, south-west and mountain Victoria, and the western slopes of the NSW southern ranges. Winds to the south of the low will swing from northerlies to easterlies, also leading to heavy falls across northern and eastern Tasmania. The forecast is more complex for Gippsland, with rainfall intensity dependent on whether the low track south to Tasmania or into eastern Bass Strait from Monday. The map below shows how much rain could accumulate over a five-day period, which would represent the heaviest falls in a year or two for some regions, including: As with most powerful fronts and lows, this weekend's system will generate a belt of strong winds. The Bureau of Meteorology has already issued warnings for strengthening north-westerly winds ahead of the first front for Friday and are likely to reissue warnings for areas of the coast and ranges when the low spins up near Bass Strait. The region likely to face the full force of the low on Saturday is along the coast near the SA-Vic border, where gusts may exceed 100 kilometres per hour, strong enough to bring down trees and lead to damage and power outages. Damaging gusts may also impact central SA and the NSW ranges on Saturday, before the threat eases slightly from Sunday onwards.
