Early cold winter air has moved north to Alice Springs, where Wednesday’s noon temperature was only 10ºC. So why is it so cold in the season?
The nation trembles collectively on the first day of winter when a cold pot reaches the third day, but an even longer cold season is expected next week.
This week’s temperatures dropped to below 10 degrees Celsius below average, low enough to break a handful of fall records in Victoria on Tuesday, including Avalon, where the high only reached 9.2 degrees Celsius.
Mountain towns woke up to a white winter that began on Wednesday after night snowfall in Trentham and Macedon in Victoria, and Jindabyne, Orange and Oberon in NSW.
The hills around Canberra even received dust while the alpine resorts hosted up to 50 cm for the last 48 hours.
Cold air has advanced north to Alice Springs, where Wednesday’s noon temperature was only around 10ºC.
So why is it so cold in the winter?
The air currently moving in Southeast Australia originated near the Antarctic coast last weekend, so it is naturally quite cold.
This polar air mass will move off the coast of NSW overnight, allowing temperatures to warm up with one or two ice cubes for Thursday and Friday, but Antarctic air is already packing its bags for a another trip north during Friday and Saturday.
This next mass of cold air will hit the Australian coast from Sunday, and will remain at least until Thursday next week.
It’s five days of cold, windy and rainy weather for the southeastern states with the usual winter mix of small hail and thunder.
During this period, temperatures will drop to 5 ºC below average, a significant amount for winter, when temperatures are usually quite stable, unlike summer which can cause fluctuations of 20 ºC in 24 hours.
Snow is likely to return to the mountains and could reach as far north as the NSW North Tables in the middle of the week.
For the Alps, the next round of snow will start as early as Friday before turning into a full-blown snowstorm over the weekend.
Sunday is likely to bring the heaviest snow, as almost half a meter could fall in just 24 hours.
Moderate snow should continue from Monday to Wednesday, bringing the total storm close to one meter.
Meteorologists and snow enthusiasts rely on Snowy Hydro data to measure snow conditions and make historical comparisons because the Meteorological Office does not keep records of snowfall.
Since the 1950s, Snowy Hydro has been doing weekly snow depth readings to calculate spring fusion for power generation.
The data show that a depth of natural snow of more than 84 cm on the opening weekend would make 2022 the best start to the season since 1968, when 146 cm had already accumulated.
For those closer to sea level, the system will bring more rain, more intense to regions exposed to westerly winds.
The map above shows a 7-day rain forecast and possibly a 100 mm drop on the west coast of Victoria and Tasmania by Thursday next week.