Guest post by Mike Jonas
Snow levels are important to the people of Australia’s Snowy Mountains because the ski industry provides a large proportion of the region’s income. There has been a series of scare stories from the Sydney Morning Herald (SMH) newspaper, and Australia’s National broadcaster, the ABC, about disappearing snow. For example, SMH reported back in 2011 that “AUSTRALIA’S ski slopes could be completely bare of natural winter snow by 2050 unless concerted action is taken against global warming“, and the ABC and SMH have wasted no opportunity over the years to reinforce that message.
There are, unsurprisingly, many people in the Snowies who think their snow will disappear within about 30 years. After all, if prospects were that bad in 2011, and with the gloom and doom messages getting more strident every year, prospects must be truly dismal by now. Mustn’t they?
Snowy Hydro, the Snowy Mountains hydropower company that supplies about a third of Australia’s renewable electricity, measures snow depths because it needs to know how much water it is going to get from the snow melt each year.
They provide a chart of the snow depth here. The data is collated from seven stations at Spencers Creek, between Perisher and Charlotte Pass.
I put the annual max depth into a spreadsheet and plotted it.
The linear trend was a loss of less than half a cm (0.2 in) per annum. Not exactly scary. And the data isn’t that accurate anyway – in recent years, they have only reported the depth to the nearest cm.
To my eye, the level has been picking up since about 2006.
I added in a 3rd-order polynomial fit (the curved line), which shouldn’t be taken too seriously because the data is only over a short period and the early data is highly variable. It’s an interesting way of looking at the data, nothing more. And it should be noted that the peak and trough in the curve are close enough to the end points to possibly be end-effects.
I looked for other historical records of snow depth that went up to 2018, and found only one – for the ski resort of South Perisher. South Perisher is very close to Spencer’s Creek, and its data is very similar to Snowy Hydro’s, but the data starts in 1954 so I did the same graph for South Perisher :
The peak on the curved line has moved to the left, and both peak and trough could still just be end-effects. But – and I think this matters – the linear trend for the 1954-2018 series was stronger at -0.76cm p.a. than the 1978-2018 series at -0.48cm p.a. This is just the sort of effect that could be expected from data with a multi-decadal cycle in it. [NB. That doesn’t prove there’s a cycle – the time period of the data is too short.]. There was some South Perisher data for 2019, but it had not reached maximum in the given data so I left it out of the graphs.
One last point to note: the last two years’ (2017, 2018) snow levels have been above-average on both time-scales.
Even the 2019 depth for South Perisher, which had not yet reached maximum in the given data, is higher at 203cm.
Conclusion
The data shows that the rate of snow loss is slowing, not accelerating, and that snow levels might even be increasing again. And that’s good news for Australia’s ski industry.
I hesitate to make any kind of forecast or prediction, but it does look very likely that all messages of impending doom are badly wide of the mark.
Mike, you write, “Snowy Hydro, the Snowy Mountains hydropower (sic) company that supplies about a third of Australia’s renewable electricity,…” Here in the Wonderland of California hydro power is, by legislative fiat, not renewable. Since California prides itself on leading the way in all things progressive, I am certain that it is only a matter of time before the Oz political and evironmental classes follow our lead and Snowy Hydro can stop measuring the snow that will have ceased to exist.
Perisher opened the sky season weeks early and closed weeks later this year.
Longest season in memory apparently.
So there’s that.
Snow levels in Australia are probably declining now because it’s springtime in Australia.
Not to fear, the snow will be back next winter.
Peter Hannam at the Sydney Morning Herald doesnt seem to agree.
https://www.smh.com.au/environment/climate-change/snowy-retreat-climate-change-puts-australias-ski-industry-on-a-downhill-slope-20170804-gxp74h.html
Any opportunity for a spin on climate extinction Hannam is right at the front of the queue. He has posted some seriously flawed pieces but not a surprise for the SMH.
Climedia hacks literally make up these reader baiting articles in a few minutes of their time. Occasionally they talk to someone professing to be an expert over the phone before penning their panic piece. It’s a shame they get paid by the word. They should be fined for making the readers stupider with their “information journalism”.
Recall also that the 60s and 70s were the years of ice age predictions, so you might be starting from a high level
An interesting article Mike and I agree with your conclusions. However your presumptions about the basic data are not correct! You should always use data from the original source if this is possible.
Both the “South Perisher” and the “Snowy Magazine” data are not original and were all measured by the Snowy Mountains Hydroelectic Authority (SMHEA) and later by Snowy Hydro. These data have been collected at a special survey site at Spencer’s Creek since 1954. Spencer’s Creek is about 6 km southwest of Perisher Valley at an elevation of 1,830 m. The data are all available on the Snowy Hydro website, snowyhydro.com.au Look for their “Snow Depth Calculator” page.
A couple of years ago I did an analysis of snow depth trends at SpencersCreek, which is probably still applicable. The peak snow depth in 2019 was 226 cm which indicates that the reduction in snow depth continues to be very slight. https:/briangunterblog.wordpress.com/2016/05/22/snow-depth-trends-in-snowy-mountains-australia/
That is good news for the ski industry and Australia in general. Not to say that the weather doesn’t cause bad effects on other industries. Trying to help the environment has so much things to consider.
With trying to move to clean energy, while snow itself doesn’t hurt efforts that much, hail does. It isn’t a secret that hurricanes and hail can damage solar panels and most likely wind turbines aswell.
https://www.ablison.com/solar-panels-hail-and-hurricanes/
Back above on Nov 1st are 3 exchanges between me and Mike Jonas regarding 3rd order curve fitting. I thought a further reply may get lost so am attaching as a new thread.
The attached link is to a screen image of an Excel file illustrating some aspects of 3rd order curve fitting.
https://docs.google.com/document/d/1zYXhxYCw6i7A4PnvqTgQLx7uBMLerYfZ8GcNf12QlNE/edit?usp=sharing
Firstly 5 values were chosen of a cubic nature. Fig 1 shows a 3rd order fit and the resulting formula.
Fig 2 uses 31 values generated from that formula and a subsequent 3rd order curve fit.
Figs 3 to 5 show 3 segments of the 31 values and a 3rd order curve fit.
Fig 3 uses all the values between the trough and peak.
Figure 4 uses a smaller subset of 11 points.
And Fig 5 only 5 values from the central region.
These last 3 plots all, as expected, give the correct 3rd order formula but in my opinion if confronted with the set of values on each graph I would not have attempted a 3rd order fit, particularly in fig 4 and 5 which only a linear fit would suffice given that in reality some errors in readings would also come into the assessment.
In fig 3 the curve is like a “S” curve or part of a sinusoidal curve and some thought of the possible physical processes would help decide but again a 3rd order curve may not be suitable.
But a secondary aspect of this is the use of extrapolation as the highest order term will quickly dominate once outside the range of values. Extrapolate and be Damned. I know Mike has not attempted any predictions but too many loud voices out there are too eager to carry out quite long-term extrapolation, sometimes on quite short term (25 years) information.
SNOW REPORT FOR OUR SNOWY MOUNTAINS 11/08/2019 ITS SNOWING SUMMER AROUND THE CORNER …https://www.ski.com.au/snowcams/australia/nsw/perisherblue/perisher-bluecow.html