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#1331335 - 10/06/2015 03:53 Snow chat South Australia.
Unstable Offline
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Registered: 09/01/2007
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Loc: Adelaide
This is a chatty thread for SA snow-related items and discussion when there's no other thread that's more appropriate for them (eg the Snow in South Australia thread or the South Australian and Adelaide day to day forecasting thread or the Falling snow photography in SA: suggestions for getting better results thread or a specific weather system thread or ... ).

A graph relating to climate change caught my eye on the internet and I went to the source and copied two graphs from among quite a few. The source is: Intergovernmental Panel on Climate Change
"Climate Change 2013: The Physical Science Basis"
IPCC Report Graphics
http://www.ipcc.ch/report/graphics/index.php?t=Assessment%20Reports&r=AR5%20-%20WG1&f=Chapter%2002

If I interpret the graphs below correctly, they suggest that the best scientific estimates of the global surface temperatures indicate they have risen a bit over one degree C since 1850 to 1920 when they were relatively stable. If that is approximately correct and if that happens to relate is a simple direct way to snowfalls in South Australia, I could speculate that the approx 1 degree rise may have resulted in a significant fall in the frequency and intensity and volume of snowfalls in SA.



Figure 2.14 | Global annual average land-surface air temperature (LSAT) anomalies relative to a 1961–1990 climatology from the latest versions of four different data sets (Berkeley, CRUTEM, GHCN and GISS).



Figure 2.16 | Global annual average sea surface temperature (SST) and Night Marine Air Temperature (NMAT) relative to a 1961–1990 climatology from gridded data sets of SST observations (HadSST2 and its successor HadSST3), the raw SST measurement archive (ICOADS, v2.5) and night marine air temperatures data set HadNMAT2 (Kent et al., 2013). HadSST2 and HadSST3 both are based on SST observations from versions of the ICOADS data set, but differ in degree of measurement bias correction.

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#1331407 - 11/06/2015 03:48 Re: Snow chat South Australia. [Re: Unstable]
Unstable Offline
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I need to make a correction to a comment I made in the above post. I commented "If I interpret the graphs below correctly, they suggest that the best scientific estimates of the global surface temperatures indicate they have risen a bit over one degree C since 1850 to 1920 when they were relatively stable." That only applies to the top graph "Figure 2.14 | Global annual average land-surface air temperature (LSAT) anomalies ... " In the second of the two graphs above: "Figure 2.16 | Global annual average sea surface temperature (SST) and Night Marine Air Temperature (NMAT) ... " the rise is approximately three-quarters of a degree C.

On another subject, SUPER CELL posted in the "Snow in South Australia" thread on 27/03/2015 "I have a feeling we will see a much better chance of snow at Mt Lofty this year (at least 2 events) I have absolutely nothing to use to back this up....just gut feeling. I will happily eat my hat, or beanie if it doesn't happen smile".
I don't know of any way to predict the chances of snow falling in SA in any year Super Cell, either trying to predict in late March when you posted, or from any other day eg June 11th. There may be no way, the chances of snow events could vary at random with the only (theoretically) known figure being the long term annual average. More likely it's complex eg perhaps the number of falls of snow in the previous year is a useful predictive factor. When a complete history of known records is compiled a statistical analysis may reveal useful indicators.

I did notice this autumn that we had two or three weather systems I thought might well have produced snow if the exact same weather systems had occurred in mid to late winter. Maybe that's a positive indicator but maybe on the other hand the onset of el nino if it does onset in SA may be a negative indicator. I do have a feeling though that "I have a feeling ..." will not figure prominently in the list of useful predictive factors when the past record has been fully analysed. I hope it does but somehow I doubt it wink
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#1331614 - 13/06/2015 20:14 Re: Snow chat South Australia. [Re: Unstable]
Seira Offline
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Registered: 27/08/2003
Posts: 7092
Loc: Adelaide Hills.
A general rule I heard – if temp on SA ranges is below x degrees C, it will snow on Alps x days later smile with westerlies. I think the x’s might be 10 and 1-2, but not sure...

Work backwards maybe grin .
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#1331661 - 14/06/2015 17:58 Re: Snow chat South Australia. [Re: Unstable]
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What we really want to know Naz is the work backwards bit - what temps in the eastern states snowfields will predict snow here in 1-2 days with easterlies! wink
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#1333657 - 06/07/2015 21:58 Re: Snow chat South Australia. [Re: Unstable]
Seira Offline
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Registered: 27/08/2003
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Loc: Adelaide Hills.
Have a look at:

ACCESS-G wind/temp gradient 1000 EST Saturday 11th July 2015.
ACCESS-G temp/wind/hght 500 hPa same time.

I think that's cold.


Edited by -Cosmic- (naz) (06/07/2015 22:01)
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#1333666 - 07/07/2015 02:53 Re: Snow chat South Australia. [Re: Unstable]
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The first essential ingredient is for snowflakes to form up in the sky. The second essential ingredient for snow to fall on our faces, as we expectantly look upwards, is for the snowflakes not to melt for their entire journey to the ground.
Those temps sound encouraging Naz smile
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#1333742 - 07/07/2015 22:55 Re: Snow chat South Australia. [Re: Unstable]
Seira Offline
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Registered: 27/08/2003
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Loc: Adelaide Hills.
Originally Posted By: Unstable
The first essential ingredient is for snowflakes to form up in the sky. The second essential ingredient for snow to fall on our faces, as we expectantly look upwards, is for the snowflakes not to melt for their entire journey to the ground.
Those temps sound encouraging Naz smile

System [rossby-wave] might need to slingshot from the deep polar south for that...to maintain the temperature difference.
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#1334359 - 11/07/2015 13:16 Re: Snow chat South Australia. [Re: Seira]
Seira Offline
Meteorological Motor Mouth

Registered: 27/08/2003
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Loc: Adelaide Hills.
Originally Posted By: Unstable
The first essential ingredient is for snowflakes to form up in the sky. The second essential ingredient for snow to fall on our faces, as we expectantly look upwards, is for the snowflakes not to melt for their entire journey to the ground.

It made ABC news:

Quote:
Snow dusts Adelaide Hills as cold front sends temperatures plummeting

Source.
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#1334363 - 11/07/2015 13:29 Re: Snow chat South Australia. [Re: Unstable]
yep Offline
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Registered: 04/07/2013
Posts: 343
Loc: Hobart
How often does snow settle on Mt. Lofty ( as opposed to just falling down )?

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#1334952 - 13/07/2015 12:05 Re: Snow chat South Australia. [Re: yep]
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Good question yep. I don't know the answer but I'd guesstimate it's approximately once every two years on average. Due to the surrounding forest and other vegetation an observer on the summit observation area doesn't see how much snow is lying on the ground on the upper slopes, only on the fringes of the tarmac. And another problem is that other forms of ice particles can fall in greater abundance than any snow, and cover or partly cover the ground, so just seeing a white carpet doesn't tell you whether it's snow or hail or graupel or a cocktail.
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#1334964 - 13/07/2015 13:41 Re: Snow chat South Australia. [Re: Unstable]
teckert Offline
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Registered: 27/05/2001
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Loc: NE suburbs, Adelaide, South Au...
I'd go as far to suggest 4-5 years on average. If you are talking a settled cover of snow.
Just about every 1-2 years will see flakes falling.

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#1336064 - 20/07/2015 13:48 Re: Snow chat South Australia. [Re: Unstable]
Fonzie Offline
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Registered: 12/07/2015
Posts: 9
Loc: Adelaide Hills
Hi all,
I remember one time seeing snow settle around my way which would have been either in 97 or 98. One thing that stands out in my mind in that event was as I was commuting down the old down track to the city it snowed all the way down to Devil’s Elbow. It basically stopped as I turned that corner.

Cheers

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#1336102 - 20/07/2015 20:35 Re: Snow chat South Australia. [Re: Unstable]
teckert Offline
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Registered: 27/05/2001
Posts: 17498
Loc: NE suburbs, Adelaide, South Au...
would suggest that may have been August 1996? That was snow down to low levels fro the Lofties.

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#1336142 - 21/07/2015 13:23 Re: Snow chat South Australia. [Re: Unstable]
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You did well Fonzie - it's rare for snow to fall that low down on the adelaide hills smile I looked up my website and found this brief summary:
"Based on the reports I've found, there were three outstanding snow events in the decade of the 1990s.
On 21st October 1995 there was a very unusual snowfall in the Flinders Ranges, perhaps one of the most widespread falls the Flinders Ranges has seen in recorded history. I haven't found much information on the meteorological causes but I'm guestimating it may have been due in part to a developing upper low over eastern South Australia combined with a very cold south-easterly airflow near the surface coming from a long way south.
On August 18th 1996 "Snowfalls of 5cm to 7.5cm were reported from Mt Barker and Bridgewater to the southern end of the Barossa Valley" and "the State ... recorded its most widespread snow falls in 12 years". The quotes are from an article in The Advertiser. This snow event was a bonanza for locals and snowchasers alike.
Then on July 28th 1998 there was another and probably even bigger and more widespread snowfall and this too was a bonanza for locals and snowchasers. An article in The Advertiser reported ""SNOW turned the countryside ~ from Kuitpo Forest in the southern Mt Lofty ranges to the Flinders Ranges in the Mid North ~ into a winter wonderland yesterday."
Sounds like it was either the 1996 or 1998 fall. More details on this page http://sasnows.com/1990sReports/1990-99current.html
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#1336205 - 22/07/2015 07:30 Re: Snow chat South Australia. [Re: Unstable]
Fonzie Offline
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Registered: 12/07/2015
Posts: 9
Loc: Adelaide Hills
Thanks for the info. Yes it could have been either the 96 or 98 event. Cheers

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#1423332 - 15/05/2017 04:21 Re: Snow chat South Australia. [Re: Unstable]
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Registered: 09/01/2007
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Loc: Adelaide
The 1917 South Australian snow season.

On this day (almost):
May 14, 1852: Snowstorm in the Adelaide Hills.
In an article titled "SNOWFALLS In Our State" by Mr. H.A. Lindsay, published in August 1935, the author gives a second-hand account of a fall of snow in the Adelaide Hills on May 14, 1852.

"The first heavy snowfall in South Australia of which we have any record took place on the afternoon of May 14, 1852. The morning dawned cold and overcast, with a heavy westerly gale and driving showers of rain. Towards evening the wind veered to the south, and over the Mount Lofty Ranges the rain gave place to snow. A wild and terrible night followed in the hills. In a little while all traces of the roads were hidden by snow, which piled into deep drifts. The gale uprooted trees everywhere, and the coach from Adelaide was hours late in reaching Mount Barker - it arrived with the horses knocked up with the exertion of dragging the heavy vehicle through the drifts, and with the outside passengers and the driver half frozen." (source http://sasnows.com )

As we drift day by day deeper into the 2017 South Australian snow season, I'm reminded of a saying (I've adapted it slightly): "Every day brings us closer to the next snowfall". I won't mention the saying "Every day brings us closer to the next snow season without snow". During the years 2009, 2010 and 2011 I kept a close eye on the weather and an ear on the grapevine and to the best of my knowledge there were no reports of what were unequivocally snowflakes falling in South Australia in any of those years. In all subsequent years 2012-2016 inclusive there's been one or more snow events.

On the topic of trying to determine whether it's pure snow that's falling or sleet or what I call a mixed salad of ice particles and flakes, I've red that the actual crystal structure of snowflakes can be seen with a good quality magnifying glass during snowfalls by observing the unmelted flakes eg resting on your or someone else's clothing. I've never tried it but it may be a simple way of helping those of us lucky enough to be out in a snowfall to determine whether genuine snowflakes are falling. Providing it doesn't distract us from more urgent biz.

One thing I've never seen is a photo of a genuine South Australian snowflake showing a crystal pattern. There's a challenge for snow photographers, again providing it doesn't distract from higher priority activities.
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