Spring 2022 NH / Fall 2022 SH Discussion Thread

We're gonna have a severe cold front heading our way on Monday, the second last day of autumn. This is awesome for Sydney and the coastal plain due to the foehn effect (days will be relatively warm, albeit windy - i.e. "icy westerlies"). 



Expect strong winds, expect cold temperatures, expect heavy mountain snow with lighter snowfalls at lower levels below 1000 metres, expect small hail, expect flooding – and generally expect a very strong taste of winter in the last couple of days of autumn early next week. We alerted you a couple of days to the significant cold weather system that lay on the horizon for southeast Australia, and there now appears extremely likely to be a major cold outbreak by the standards of any winter month, let alone the last few days of autumn.

Weatherzone meteorologist Joel Pippard says the cold front and cut-off low will impact large parts of SA, TAS, Vic, NSW, ACT, and even southern QLD between Sunday May 29 and Wednesday June 1. The wintry weather should reach Adelaide later on Sunday, with much of SE Australia copping the most severe weather on Monday and Tuesday.

"This system will result in a broad area of damaging winds (wind gusts exceeding 90km/h), likely affecting Adelaide, Melbourne, Canberra and Sydney, and possibly Hobart and Brisbane," Joel says. "In addition, large accumulations of small hail, moderate rainfall leading to some minor flooding and low-level snow are possible."

www.weatherzone.com.au/news/confidence-building-around-mondays-freezing-storm/595047

Cuntbrook under D0 conditions. Southern AB though...

Comfortable again today with high/low of 72 F/48 F (22 C/9 C). Sun was out this morning but it's been cloudy most of the afternoon.

Splendid grazing weather for the old cow.

Skiing On Front Lawns: Flashback To The Famous May 2000 Blizzard.
( source: Weatherzone )


It's the freezing cold snowy weather system that many Australians will never forget. The most unusual aspect to it? It happened outside of winter.

In late May, 2000, a strong cold front laden with polar air surged northwards to southeast Australia, delivering snow to low levels rarely seen in any month of the year.


Image: The May 28, 2000, chart shows a very deep low pressure system with cold air from far south being brought northwards. The the dashed lines on the chart (not the isobars) indicate rainfall/snowfall. Source: BoM Analaysis Chart Archive.

Towns across New South Wales and Victoria that are usually too low for snow saw a coating of white. Gundagai, at just 230 metres above sea level, had snow on the ground. A couple of hours down the Hume Highway at Albury, snowflakes were widely reported at just 165 metres above sea level, although nothing settled.

The storm is perhaps most famous for delivering snow to Canberra Stadium on May 28 during the Wests Tigers/Canberra Raiders match (which we wrote about last year). For the record, the stadium sits at just under 600 metres above sea level.

On 28 May 2000 @raiderscanberra & @weststigers played in the snow. The Raiders narrowly defeated the Tigers 24-22. Courtesy ABC News.
Read more: t.co/Aa9Hmuf4gH#Newscaf30 pic.twitter.com/eye1pXr15j

— NFSA -National Film and Sound Archive of Australia (@nfsaonline) June 25, 2018

Canberra recorded its lowest May maximum on record of just 4.3°C that day. Other capital cities also shivered – even Sydney. Your intrepid Weatherzone reporter was collecting door-to-door for the Salvation Army Red Shield Appeal in Sydney, and while the max temp topped 17°C, that was quite likely recorded in the morning before the full force of the cold change blew through.

Thereafter, the wind was as icy as it gets. By 3 pm, enough was enough. With numb hands and icicle ears, the warmth of a pub was the only sensible option. That's when the NRL snow game appeared on the television.

Meanwhile up in the mountains, there was as you'd expect a serious blizzard. Mainland ski resorts reported a metre of snow on the ground by the time the storm cleared. But even in towns below the mountains which usually remain snow-free in even the best season, heavy snow had fallen.



A resident of Mt Beauty, Victoria (elevation just 360 metres at the bottom of the road to Falls Creek) told Weatherzone that she was skiing on her front lawn, while snowmobile tracks lined the Kiewa Valley Highway through town.

As we noted here recently on Weatherzone after the first Aussie autumn snowfall of 2022, May snowfalls don’t usually stick around till June and beyond. But this event was no ordinary May snowfall, and naturally, that metre base provided a bumper start to the ski season, with most resorts cranking up the lifts well before the traditional June long weekend opening.

Skier traffic wasn't just limited to the slopes. Richard Tribe, who founded Australia's most popular snow industry website ski.com.au in 1995, said the event generated too much web traffic for the whole site to handle.

"We had to turn off the forums, the classifieds, the snow reports and the ad-server (back in the day when websites ran their own ad-tech) just to keep the snow cams up and available," he said.

"Our web server peaked at 25 times the normal load. This was a big deal in 2000 – when most people were still on dial-up. We didn't have a bigger single day of visitors until the storm dubbed 'Snowmageddon' in 2014."

The winter of 2000 went on to be one of the best Australian ski seasons on record, with further heavy snowfalls resulting in a peak season depth of 262 cm at Snowy Hydro's official measuring site of Spencers Creek in NSW. We haven't seen a snowpack as deep since then, and perhaps in a warming climate, we never will.


But ironically, a lot of the snow went to waste that year from the point of view of businesses in the snowfields. That, of course, was the year of the Sydney Olympics, which ran from September 15 to October 1.

The peak snow depth of 262 cm occurred on September 7, but by about mid August, everyone was focused on the lead-up to the Sydney opening ceremony – and perhaps saving their money for all the partying that went on during those heady two weeks. Even the AFL and NRL Grand Finals were held early, on August 27 and September 2 respectively.

Meanwhile back here in the present day, 22 years since the famous May 2000 snow event, the weather models are suggesting a chance of something similar next Monday and Tuesday, as we've mentioned a couple of times already this week.

It's unlikely that next week's snow will amount to depths of a metre at the ski resorts (though they may get around half that much), or that snow will fall as low as it did in 2000 (the current forecast is for snow to fall to about 900 metres in NSW and Vic).

But for snow-lovers, a May weather system that even faintly resembles that 2000 storm is very exciting news indeed. Please check our snow page for the latest.

A Climate Driver Called SAM
( source: Weatherzone )


SAM is a climate driver of Australia which influences the weather of southern and eastern Australia. In fact, SAM influences the weather for many countries in the Southern Hemisphere, contributing to floods and droughts.
SAM stands for the Southern Annular Mode. It is a secondary climate driver for Australia, whereas the El Nino Southern Oscillation and the Indian Ocean Dipole are primary climate drivers.
What does the SAM measure? Around the subtropics, there is a belt of high-pressure systems called the subtropical ridge. SAM measures the relative position of these high-pressure systems. A positive SAM occurs when the highs are shifted southward toward Antarctica, while a negative SAM occurs when the highs are shifted northward over Australia. The SAM plays a role in the rainfall and temperatures because high-pressure systems direct cold fronts and moisture.

SAM tends to be in its positive phase during La Nina, which was the case for much of the year. This has contributed to above average rainfall for southeast QLD, eastern NSW and eastern VIC and below average rainfall for western TAS, southern VIC, and southeast SA.



The following pressure chart from February 26th, 2022, shows an example of a positive SAM with the highs south of Australia. This setup contributed to the extensive flooding across QLD and NSW by driving moisture onto the east coast into troughs. Notice the cold front being kept south of Australia by the high, leading to reduced rainfall for the southeast.



However, the pattern recently shifted, and SAM entered its negative phase. The pressure chart from today (May 28, 2022), shows high pressure over southern WA and SA. The highs being further northward allows cold fronts to reach southern WA and the southeastern states, with several fronts and troughs expected within the next week. The strongest cold front is expected to impact SA, VIC, NSW and TAS from Monday 30th, which will cause widespread damaging winds, extreme cold temperatures, rain, storms, and snow for the Alps.



The impacts of the different phases of SAM are quite different. It also depends on whether it is summer or winter since the subtropical ridge shifts with seasons.
SAM is expected to become neutral at the beginning of next month. However, it is not possible to forecast this climate driver beyond about two weeks.

For more information, please refer to the BOM’s information page: www.bom.gov.au/climate/sam/#tabs=What-is-SAM%3F

@rg6832614 I like how that's considered notably cool and it's still above 70 F haha

I don't like heat.

cool clouds