Observations 31st July-6th August Systems

Undies

Superspreadin the lurve
Ski Pass
May 15, 2002
22,875
19,795
1,063
Top drawer
I think the standard is to times the water content by about 10. So in this case, we would have lost about 45cm of snowpack (which looks about right, on the cams).

Or is it something else?
 

trappers

Safety not guaranteed
Moderator
Ski Pass
Jul 28, 1999
40,914
8,565
1,525
An airport
www.owithalinethroughit.com
I think the standard is to times the water content by about 10. So in this case, we would have lost about 45cm of snowpack (which looks about right, on the cams).

Or is it something else?
No, that is already factored into the calculation.

The latent heat of fusion of ice (snow) is high at 333 j/g ... so it takes ~80 times more energy to melt snow than it does to raise the temperature of the same amount of water by 1 C

The calculations above relate ONLY to the mass of snow ice loss. As I said, most of the reported "loss" will actually be in consolidation. If the pack was already well consolidated, then you would expect a lot less loss.
 
Remove ads with a
Ski Pass

robbo mcs

A Local
Ski Pass
Sep 1, 2008
5,906
28,174
563
Kenthurst / Jindabyne
Grand total loss of 4.5cm? That doesn't sound so terrible in the grand scheme of things all things considered...am I missing something?
That calculation is looking purely at the loss due to the warm rain vs near freezing rain. On top of that there is also melt purely due to the ambient temp (regardless of rain), wind effects, physical erosive effects of flowing water on top and underneath the snow, etc, etc

The amount of loss is going to vary widely from place to place, but it is not going to be pretty. However, never ceases to amaze me how well the snow pack will look following some cold temps and fresh snow, hopefully by monday ;)
 

trappers

Safety not guaranteed
Moderator
Ski Pass
Jul 28, 1999
40,914
8,565
1,525
An airport
www.owithalinethroughit.com
That calculation is looking purely at the loss due to the warm rain vs near freezing rain. On top of that there is also melt purely due to the ambient temp (regardless of rain), wind effects, erosive effects of flowing water on top and underneath the snow, etc, etc

The amount of loss is going to vary widely from place to place, but it is not going to be pretty. However, never ceases to amaze me how well the snow pack will look following some cold temps and fresh snow, hopefully by monday ;)
Exactly. Also the rain will move ice / snow and will expose thinly covered surfaces / rocks which makes the impact look worse than it is.

The warm air temperatures can have a bigger impact as that air is constantly replaced. Once a 5C rain drop has cooled to 0C it does no more damage, but when a 5C packet of air cools in contact with the snowpack, it is replaced by another, and another, and another unrelentingly. On the positive side, the heat transfer coeff for air is low (if wind is low) and it has a low specific heat too (~1j/gC vs 4 for water).
 

Star_Hawk

Obsessed with Stats
Ski Pass
Jun 23, 2022
199
481
113
Eastern Suburbs, Sydney
Thredbo Top station temp going nowhere fast unfortunately. At least it's not 5c anymore but its still far to warm for my liking.
temp.JPG
 

Ultra 3.0

Addicted
Jun 23, 2022
140
264
113
lots of high level cloud across Sydney, though trying to rain, been light all day, not enough to soak the ground, just rain already.
 
Remove ads with a
Ski Pass

Deanski

One of Us
Jun 26, 2017
279
253
163
53
Cronulla
That calculation is looking purely at the loss due to the warm rain vs near freezing rain. On top of that there is also melt purely due to the ambient temp (regardless of rain), wind effects, physical erosive effects of flowing water on top and underneath the snow, etc, etc

The amount of loss is going to vary widely from place to place, but it is not going to be pretty. However, never ceases to amaze me how well the snow pack will look following some cold temps and fresh snow, hopefully by monday ;)
Watching it each hour on the cams.....gee its copping a belting. The Guthega cam particularly showing sever damage and melt since I started monitoring this morning. Hard to watch.
 

blueandwhite

One of Us
Ski Pass
May 26, 2016
1,362
4,535
363
TQY
Partly cloudy at Buller now with lots of blue sky showing through. Plenty of people out skiing and temps going back up to 3+ again.

Not getting too cocky though as I assume we will get a lot less of a top up than the other resorts over the next few days. Hopefully those hit hardest by the rain will have forgotten about it when the snow comes and fills the gaps in again!
 

snowgum

A Local
Ski Pass
May 4, 1999
7,504
6,489
563
56
vic
But the real damage is in the consolidation of the pack. A light fluffy snow pack may reduce to half the depth when rain strikes it even though only a little bit of the snow is melted.
He he, a light, fluffy snowpack in Aussie, or funnier, Vic.

Thats a good hypothetical! :pROFL

But I accept the premise, agreed, we’re seeing quite a bit of unwanted shrinkage these last two days.
 
Remove ads with a
Ski Pass

Nidecker

A Local
Ski Pass
Aug 5, 2009
7,028
15,317
563
Alpine the dark side of snowboarding
Watching it each hour on the cams.....gee its copping a belting. The Guthega cam particularly showing sever damage and melt since I started monitoring this morning. Hard to watch.
Yeah I would imagine that will be similar, but perhaps a little better than the lower half or thredbo, which never carries much depth anyway. But the temp and the rain will flog it.
 

Chionophile

Hard Yards
Sep 15, 2014
28
131
83
Mount Glasgow
www.philhart.com
Well radar around the mountains can be horribly innacurate, but this gives some spatial sense of what's unfolded.

24 hours to 9am, then 9am-6pm today. Mount J where we might still be headed next week may have threaded the needle and got off light overnight but that gap got washed out today, so nobody missed out. Sorry the same product is not available for Vic high plains.

Rainfall 24hr to 9am 4th Aug 2022.PNG
Rainfall 9am-6pm 4th Aug 2022.PNG
 

Adaminaby Angler

One of Us
Ski Pass
Ski Pass
Jul 3, 2019
706
2,104
263
Maragle, NSW; 948 m AMSL; 35.86° S
Appears to be a classic Aussie version of a "pineapple express" that can hit even in the middle of winter over in Canada / USA. I know personally that Fernie BC is notorious for these type of events and have experienced first hand.....
Yep, this is an actual pineapple which is quite a rare occurrence in AU. In the US/EU however, these are very common.

We would have close to zero snow cover every winter, if we got these even remotely to the same frequency as NH locations. Just look at the non-existent skiing in the (southern) Appalachians which share our latitude and altitude.
 
  • Like
Reactions: xyz and Ian

GobrinIce

One of Us
Ski Pass
Jul 9, 2019
409
958
263
On trip from inner west to Dalgety last night leaving around 5: miserable traffic out to campbo, Howling winds from Campbeltown to Goulburn, sheets and sheets of rain, horrendous, until bottom edge of ACT, light rain from ACT to Cooma, misty in Cooma, fairly calm from Cooma into Dalgety around 10:30. Was least pleasant of my drives to the snow. But whenever getting out of Sydney one is filled with delight nonetheless.

Blowing wind this morning.
 

Rat trap bindings

One of Us
Ski Pass
Jul 17, 2017
449
1,036
263
On trip from inner west to Dalgety last night leaving around 5: miserable traffic out to campbo, Howling winds from Campbeltown to Goulburn, sheets and sheets of rain, horrendous, until bottom edge of ACT, light rain from ACT to Cooma, misty in Cooma, fairly calm from Cooma into Dalgety around 10:30. Was least pleasant of my drives to the snow. But whenever getting out of Sydney one is filled with delight nonetheless.

Blowing wind this morning.
Dalgety? I observe you overshot the drive to the snow, and I’m glad you clarified what you where blowing…
 
Remove ads with a
Ski Pass
Remove ads with a
Ski Pass

Log in

or Log in using