Fishnhunt New Zealands main hunting and Fishing Forum. millions of posts on fishing and hunting, dogs, 4x4 vehicles, outdoors and much more Welcome, Guest. Please Login or Register
Page Index Toggle Pages: [1]  Send TopicPrint
Hot Topic (More than 30 Replies) Above the snowline in the South Island (Read 41737 times)
headcase
Global Forum Guide
Donor Member
*****
Offline


Former Youngest Person
in the World

Posts: 27317
Location: Ponsenby
Joined: Jul 9th, 2007
Gender: Male
Above the snowline in the South Island
Jul 31st, 2009 at 12:30pm
Print Post  
The snowpack throughout the South Island is generally weak and unstable at the moment. Numerous avalanches both with natural and human triggers have been recorded. There are layers deep in the snow that have a very weak bond to each other. I noted on a trip up the Godley last week there were signs of big and small avalanches  everywhere, the bigger ones mainly on Easterly aspects, but every aspect, especially at higher altitude had fresh avalanche sign. The tragic death of one skier last week, and numerous other occurrences, bring home the inherent dangers hidden in a weak snowpack.

for those of you that are hunting Tahr above the snowline caution should be exercised.

Here is a small excerpt from "the backcountry travel advisory " released on the 28th, and it is still current. It applies more or less for all areas in the South Island.


Quote
TRAVEL ADVISORY
Well east of the divide the snowpack is shallow and weak, with reports of widespread woomphing coming in over the last few days. Heavy snow loadings and windslab exist lee to the western quarter, about and east of the divide. This is spread over an increasingly weak snowpack the further out east from the divide.All steep slopes should be treated with suspicion, as with slopes below ridgeline lee to the western quarter. There is such a wide variability of snowpack conditions throughout the district, that a positive snow profile test on one slope does not represent snowpack conditions on
similar slopes. New snow is now falling with westerly winds about the divide which maybe loading lee slopes to threshold, or reloading slopes that have previously run. Stick to gentle terrain and travel with caution in the backcountry at the moment.
Unquote

"woompfing" refers to the sound the snowpack makes as you walk over the surface and it settles a cm or two, over a large area. This is often accompanied by the propogation of a fracture line in the snow and an avalanche is also highly likely. One would hear a very audible woompf. If you ever hear it as you move over snow, the best course of action is retrace your steps, drive home and sit in front of the fire.

more deatiled info for your area can be obtained at
http://www.avalanche.net.nz
happy hunting..  Smiley
« Last Edit: Aug 6th, 2009 at 12:13pm by headcase »  

“We either make ourselves miserable, or we make ourselves strong. The amount of work is the same.”
Back to top
WWW  
IP Logged
 
MattDog
Ex Member


Re: Above the snowline in the South Island
Reply #1 - Jul 31st, 2009 at 4:16pm
Print Post  
cheers - wise words.

I've just flown back from Queenstown to ChCh and she was a bumpy flight. Plenty of wind about along the east edge of the range all right.
  
Back to top
 
IP Logged
 
blacks
Full Member
***
Offline


Red Stag SA. 302 7/8 DS

Posts: 137
Location: SE/South Australia
Joined: Mar 13th, 2009
Gender: Male
Re: Above the snowline in the South Island
Reply #2 - Aug 1st, 2009 at 2:53am
Print Post  
Bloody Hell, not really what I wanted to hear since i am heading up there next week....... Undecided

Thanks for the heads up Headcase. How are upcoming conditions looking? What is the best source of up-to-date infor and forecasts?

Cheers,

blacks
  

You won't shoot anything at home on the couch...
Back to top
 
IP Logged
 
headcase
Global Forum Guide
Donor Member
*****
Offline


Former Youngest Person
in the World

Posts: 27317
Location: Ponsenby
Joined: Jul 9th, 2007
Gender: Male
Re: Above the snowline in the South Island
Reply #3 - Aug 1st, 2009 at 8:41am
Print Post  
Blacks, youll be fine. In the east its still pretty hairy but you can still go there. Id just be picking nice snow free ridges and staying out of slopes that have snow loaded into them by the wind. Lots of westerly facing slopes have been scoured by the wind back to a hard icy layer and the snow has been deposited in the lee. If your moving around below those loaded slopes Id also be a little cautious about walking up any narrow gullies  under the snow line.

anyway, All the Tahr that ive seen in the last week and the two that I heard got shot yesterday in my area, were all just on or under the snow line on sunny faces.


Go get em..  Smiley
« Last Edit: Jul 11th, 2011 at 2:56pm by headcase »  

“We either make ourselves miserable, or we make ourselves strong. The amount of work is the same.”
Back to top
WWW  
IP Logged
 
blacks
Full Member
***
Offline


Red Stag SA. 302 7/8 DS

Posts: 137
Location: SE/South Australia
Joined: Mar 13th, 2009
Gender: Male
Re: Above the snowline in the South Island
Reply #4 - Aug 2nd, 2009 at 3:04am
Print Post  
Thanks again Mate! Looking forward to it, with a little trepidation!! Wink

blacks
  

You won't shoot anything at home on the couch...
Back to top
 
IP Logged
 
headcase
Global Forum Guide
Donor Member
*****
Offline


Former Youngest Person
in the World

Posts: 27317
Location: Ponsenby
Joined: Jul 9th, 2007
Gender: Male
Re: Above the snowline in the South Island
Reply #5 - Aug 3rd, 2009 at 2:28pm
Print Post  
Another avalanche death yesterday at Coronet Peak. It’s not to be trifled with at the moment. The deep instabilities in the snowpack and strong winds from varying directions make back country travel challenging at the moment.
  

“We either make ourselves miserable, or we make ourselves strong. The amount of work is the same.”
Back to top
WWW  
IP Logged
 
headcase
Global Forum Guide
Donor Member
*****
Offline


Former Youngest Person
in the World

Posts: 27317
Location: Ponsenby
Joined: Jul 9th, 2007
Gender: Male
Re: Above the snowline in the South Island
Reply #6 - Aug 6th, 2009 at 12:06pm
Print Post  
For anyone wanting uptodate info on the snow situation, the link to the MSC backcountry bulliten is here.

www.avalanche.net.nz

and as an aid to interpreting the bulletin below are a few terms and commonly used names.

Glossary of commonly used terms in the NZMSC Backcountry Avalanche Advisories (www.avalanche.net.nz)

Avalanche path
A terrain feature in which an avalanche occurs, this is normally split into the start zone, track and runout zone

Avalanche terrain
Any terrain which has the potential to form or be part of a snow avalanche

Bonding
Refers to a snowpack which has undergone some metamorphism and has many links between the individual snow grains, generally leading to a stronger “bonded” snowpack. (or a weakening, depening on teh situation. ed. hc)

Cornice
An overhanging mass of wind sculpted snow projecting beyond the crest of a ridge

Crust
A hard surface layer which can be formed by solar radiation, wind or rain which has the potential to cause instability when buried.  ( or simple rise in air temperature
amd then a cooling of teh surface layer. Ed. HC)

Freezing level
The elevation at which the air temperature is at 0° Celsius

Half (1/2)
Used with compass directions, e.g. “lee to the easterly half” refers to the aspects facing west from north through to south.

Instability
A weakness or lack of stability indicating that additional loads will result in a given probability of avalanche occurrence.

Lee (leeward)
The side of a mountain protected from the wind

Loose snow (avalanche)
A type of avalanche which originates at a point and spreads out as it descends.

Melt-freeze
A metamorphic process when snow changes from a solid to a liquid and back again and may result in the formation of a crust.

Pockets
Small isolated terrain features

Quarter (1/4)
Used with compass directions, e.g. “lee to the easterly quarter” refers to the aspects facing northwest through to southwest.

Runout zone
The area at the bottom of an avalanche path where an avalanche starts to decelerate and comes to rest, this is where the debris is located after an avalanche has occurred.

Safe travel technique
The use of appropriate terrain to move given the posted danger scale (e.g. stay to ridges and well away from runout zones, or slopes less than 30°)

Shady aspect
The side of a mountain protected from the sun

Slab
A cohesive layer of snow

Sliding hazard
A hazard posed by very hard or icy conditions, also known as ‘slide for life conditions’.

Solar aspect
The side of a mountain exposed to the sun

Start zone
The area at the top of an avalanche path in which unstable snow may fail. Most commonly has an angle greater than 25 degrees.

Terrain traps
Terrain features which in the event of an avalanche would compound the effect (e.g. gullies, small bowls)

Track or Path
The area which connects the start zone and runout zone, this can be either confined or unconfined.

Unsupported slope
Slopes which are not being supported by the terrain, e.g convex rolls

Weak layer
A layer in the snowpack identified as a possible failure plane. 

Wet snow
Snow with a water content greater than 3% and has a temperature of 0° Celsius

Whumphing
The sounds associated with the rapid settlement or collapse of a snowpack, when weighted.

Wind loading (sometimes reffered to a crossloading depending on terrain shape)
The transport of snow by the wind causing an additional build up of snow on a lee slope

Wind slab
A cohesive layer of snow caused by wind loading

Windward
The side of a mountain exposed to a wind

(and an additional one that Ive added. Pillow A confined small deeper area of wind blown snow that has collected in the lee of a ridge or terrain feature. ED.HC )
« Last Edit: Jul 11th, 2011 at 3:10pm by headcase »  

“We either make ourselves miserable, or we make ourselves strong. The amount of work is the same.”
Back to top
WWW  
IP Logged
 
yogi
Donor Member
*****
Offline


Patience, persistence
and perseverance

Posts: 644
Location: Oamaru
Joined: Apr 22nd, 2009
Gender: Male
Re: Above the snowline in the South Island
Reply #7 - Aug 9th, 2009 at 9:34am
Print Post  
I think most hunters that venture out tahr hunting in the winter would benefit from a basic alpine skills course run by the mountain safety council. They cover basic stuff such as use of ice axe and crampons, building snow caves, and avalanche awareness.
We did  a course up at fox peak ski field and found it to be quite informative and useful.
  

Just got to keep on chipping away!
Back to top
 
IP Logged
 
GET SOME
Full Member
***
Offline


huntsoc old boy

Posts: 156
Location: mt hutt/wellington
Joined: Feb 27th, 2007
Gender: Male
Re: Above the snowline in the South Island
Reply #8 - Aug 11th, 2009 at 10:14am
Print Post  
Heres a tutorial thing I organised for HUNTSOC, I think the guys gained allot

http://www.fishnhunt.co.nz/forum/YaBB.cgi?num=1249878427

Hopefully it'll be enough to keep the kids out of trouble
  

Dont blame the animal..... Blame the meat
Back to top
YIMAIM  
IP Logged
 
headcase
Global Forum Guide
Donor Member
*****
Offline


Former Youngest Person
in the World

Posts: 27317
Location: Ponsenby
Joined: Jul 9th, 2007
Gender: Male
Re: Above the snowline in the South Island
Reply #9 - Aug 11th, 2009 at 6:15pm
Print Post  
Good stuff Get some. They say a little knowledge can be a dangerous thing, but I’d say that Alpine Safety has to be learned in small steps and any education in a safe and controlled environment is positive, and will help hunters and others to make sounder and safer decisions when they are needed.  Smiley
  

“We either make ourselves miserable, or we make ourselves strong. The amount of work is the same.”
Back to top
WWW  
IP Logged
 
Kickstart
Online Forum Guide
Donor Member
Staff
*****
Offline


Gas leak solved, yeah...NAAAA
NAAA run!!

Posts: 7699
Location: Banjoville - Nth Canty
Joined: Sep 26th, 2007
Re: Above the snowline in the South Island
Reply #10 - Aug 13th, 2009 at 10:10pm
Print Post  
Thanks Headcase - I have read this a couple of times now, and believe it or not... its actually soaking in...

RS described very vividly just the situation you warned about... thanks.l
  

Back to top
 
IP Logged
 
headcase
Global Forum Guide
Donor Member
*****
Offline


Former Youngest Person
in the World

Posts: 27317
Location: Ponsenby
Joined: Jul 9th, 2007
Gender: Male
Re: Above the snowline in the South Island
Reply #11 - Aug 16th, 2009 at 12:27pm
Print Post  
Some more sad news.

Totara Peak, Methven

15:20 15-08-2009
Police advise that the man killed in the avalanche at Totara Peak yesterday was -edited-, aged 38 years. He was a heli-ski guide who was a Methven resident.

No further information is available.

As at 15.08.09, 1520 hrs

District:
Canterbury
Description of Incident:
Avalanche Victim Named


Its when you think you know it all that nature comes around an slaps you in the face.  Heli ski guides are particulary exposed because they are alway looking for fresh untracked powder to ski.. on the front line so to speak.  Tongue
« Last Edit: Jul 11th, 2011 at 3:15pm by headcase »  

“We either make ourselves miserable, or we make ourselves strong. The amount of work is the same.”
Back to top
WWW  
IP Logged
 
wobblyboot
Forum Senior
****
Offline


whose that following me

Posts: 693
Location: canterbury
Joined: Jan 6th, 2008
Gender: Male
Re: Above the snowline in the South Island
Reply #12 - Aug 16th, 2009 at 3:15pm
Print Post  
Thanks for that Headcase, He's a friend of a friend.and will be sadly missed.
Ive got two or three avalanche stories, once at the head of Griffiths stream, Wilberforce, once near Aspiring and once on Barrier at the head of the Gertrude Valley.  Yup, we think we got it all sussed, Nowadays I wouldnt go anywhere in winter without the transceiver, shovel and probe and a mate as ya cant really probe  for yourself. chhers
  

only dirty people wash
Back to top
 
IP Logged
 
Kickstart
Online Forum Guide
Donor Member
Staff
*****
Offline


Gas leak solved, yeah...NAAAA
NAAA run!!

Posts: 7699
Location: Banjoville - Nth Canty
Joined: Sep 26th, 2007
Re: Above the snowline in the South Island
Reply #13 - Aug 16th, 2009 at 5:20pm
Print Post  
Sorry to hear...

At least he was doing what he loved, poor excuse tho.. any life lost  Undecided
  

Back to top
 
IP Logged
 
headcase
Global Forum Guide
Donor Member
*****
Offline


Former Youngest Person
in the World

Posts: 27317
Location: Ponsenby
Joined: Jul 9th, 2007
Gender: Male
Re: Above the snowline in the South Island
Reply #14 - Aug 16th, 2009 at 5:34pm
Print Post  
wobblyboot wrote on Aug 16th, 2009 at 3:15pm:
Thanks for that Headcase, He's a friend of a friend.and will be sadly missed.
Ive got two or three avalanche stories, once at the head of Griffiths stream, Wilberforce, once near Aspiring and once on Barrier at the head of the Gertrude Valley.  Yup, we think we got it all sussed, Nowadays I wouldnt go anywhere in winter without the transceiver, shovel and probe and a mate as ya cant really probe  for yourself. chhers


Do you hunt around the snowline Wobbly boot? and as a hunter do  you bother to take your transciever also? Just interested.  Smiley

RIP
  

“We either make ourselves miserable, or we make ourselves strong. The amount of work is the same.”
Back to top
WWW  
IP Logged
 
wobblyboot
Forum Senior
****
Offline


whose that following me

Posts: 693
Location: canterbury
Joined: Jan 6th, 2008
Gender: Male
Re: Above the snowline in the South Island
Reply #15 - Aug 17th, 2009 at 8:34pm
Print Post  
if you are hunting or climbing by yourself then it's a waste of time carrying a transceiver, unless you want someone to find your bod.
after a drive up the mt cook road i would not go near any of the creeks off the road at the mo, fracture lines and seriously loaded cornices everywhere.
  

only dirty people wash
Back to top
 
IP Logged
 
POINTBLANK
Forum Senior
****
Offline



Posts: 915
Location: Nelson
Joined: Dec 15th, 2006
Gender: Male
Re: Above the snowline in the South Island
Reply #16 - Aug 18th, 2009 at 1:24pm
Print Post  
when I go snowboarding I take my transceiver. When I go hunting I don't.
The main reason is, as wobblyboot pointed out, it's not going to help you unless your mates have transceivers (+ shovel & probe) too. None of my hunting mates have avi rescue gear. It does give me the shits hunting in country knowing I wouldn't be skiing it without gear  Undecided
then again while hunting I'm not exactly hucking myself off cliffs and ripping across big, open, exposed faces.
We always try to pick the most conservative routs and if snowpack stability looks dodgy it's home time.
Its surprising more hunters don't run into grief. I bet we don't hear the half of what happens out there, close calls etc.


  
Back to top
 
IP Logged
 
wobblyboot
Forum Senior
****
Offline


whose that following me

Posts: 693
Location: canterbury
Joined: Jan 6th, 2008
Gender: Male
Re: Above the snowline in the South Island
Reply #17 - Aug 19th, 2009 at 7:39pm
Print Post  
my biggest fear with avalanches is getting buried and having some bugger come along and poke me in the eye with his probe,  be a pain in the ass wouldnt it,
  

only dirty people wash
Back to top
 
IP Logged
 
headcase
Global Forum Guide
Donor Member
*****
Offline


Former Youngest Person
in the World

Posts: 27317
Location: Ponsenby
Joined: Jul 9th, 2007
Gender: Male
Re: Above the snowline in the South Island
Reply #18 - Aug 19th, 2009 at 7:50pm
Print Post  
wobblyboot wrote on Aug 19th, 2009 at 7:39pm:
my biggest fear with avalanches is getting buried and having some bugger come along and poke me in the eye with his probe,  be a pain in the ass wouldnt it,


no it would be a pain in the eye  Grin

It seems that hunters above or near the snowline are faced with a special set of circumstance. Often alone or hunting apart, there is not much point in wearing a rescue beacon.

Beacons need two persons to function ,, one on the victim and the other in the hands of an observer /rescue-er who can reach the victim quickly, locate him , and free him.


« Last Edit: Jul 11th, 2011 at 3:20pm by headcase »  

“We either make ourselves miserable, or we make ourselves strong. The amount of work is the same.”
Back to top
WWW  
IP Logged
 
ghosthunt
Full Member
***
Offline


I Love The FishNhunt Forum

Posts: 250
Location: Southern Lakes
Joined: Mar 28th, 2009
Gender: Male
Re: Above the snowline in the South Island
Reply #19 - Aug 20th, 2009 at 5:26pm
Print Post  
I am very surprised more hunters have not being killed in the NZ mountains. I think most hunters do not understand the danger and have alot of luck on there side. Big thing to remember is that a Avo can carry on pass the snow line!!!
If we are hunting in the in or above snow line everyone in the party has a trans, shovel and prode and more importantly knows how to use it.
  
Back to top
 
IP Logged
 
wobblyboot
Forum Senior
****
Offline


whose that following me

Posts: 693
Location: canterbury
Joined: Jan 6th, 2008
Gender: Male
Re: Above the snowline in the South Island
Reply #20 - Aug 24th, 2009 at 8:13pm
Print Post  
here's a site I find useful, http://www.softrock.co.nz/mg/index.php?page=2 if you are heading into the scrub then this and headcase's stuff are useful reference's
remember
old and cunning will always triumph over youth and skill
  

only dirty people wash
Back to top
 
IP Logged
 
Dairyispoison
Banned
**
Offline



Posts: 5444
Joined: Aug 6th, 2007
Gender: Male
Re: Above the snowline in the South Island
Reply #21 - Aug 25th, 2009 at 7:13pm
Print Post  
headcase wrote on Aug 19th, 2009 at 7:50pm:
wobblyboot wrote on Aug 19th, 2009 at 7:39pm:
my biggest fear with avalanches is getting buried and having some bugger come along and poke me in the eye with his probe,  be a pain in the ass wouldnt it,


no it would be a pain in the eye  Grin




Imagine if you were face down - it could be a real pain in the brown eye! Cheesy
  
Back to top
 
IP Logged
 
wobblyboot
Forum Senior
****
Offline


whose that following me

Posts: 693
Location: canterbury
Joined: Jan 6th, 2008
Gender: Male
Re: Above the snowline in the South Island
Reply #22 - Aug 26th, 2009 at 7:30am
Print Post  
You do not have to be above the snowline to get taken out, for instance if you are cruising up to Huxley Forks check out the damage to the beech forest on the true right, those trees have been blown over uphill by the windfrom  an avo coming offthe faces above you. The snow debris may not have reached where you are, if the avo wind can do this to trees, then what chance do you stand. You will be having a blast, thats for sure! there are numerous other areas like this.
  

only dirty people wash
Back to top
 
IP Logged
 
headcase
Global Forum Guide
Donor Member
*****
Offline


Former Youngest Person
in the World

Posts: 27317
Location: Ponsenby
Joined: Jul 9th, 2007
Gender: Male
Re: Above the snowline in the South Island
Reply #23 - Aug 26th, 2009 at 9:15am
Print Post  
wobblyboot wrote on Aug 26th, 2009 at 7:30am:
You do not have to be above the snowline to get taken out, for instance if you are cruising up to Huxley Forks check out the damage to the beech forest on the true right, those trees have been blown over uphill by the windfrom  an avo coming offthe faces above you. The snow debris may not have reached where you are, if the avo wind can do this to trees, then what chance do you stand. You will be having a blast, thats for sure! there are numerous other areas like this.


fully agree. Looking for sign of areas below the tree line that have been blown over by avalanche is good policy.. Its useually pretty obvious, the paths that are regularly given a beating..
  

“We either make ourselves miserable, or we make ourselves strong. The amount of work is the same.”
Back to top
WWW  
IP Logged
 
headcase
Global Forum Guide
Donor Member
*****
Offline


Former Youngest Person
in the World

Posts: 27317
Location: Ponsenby
Joined: Jul 9th, 2007
Gender: Male
Re: Above the snowline in the South Island
Reply #24 - Aug 26th, 2009 at 11:53pm
Print Post  
wobblyboot wrote on Aug 24th, 2009 at 8:13pm:
here's a site I find useful, http://www.softrock.co.nz/mg/index.php?page=2 if you are heading into the scrub then this and headcase's stuff are useful reference's
remember
old and cunning will always triumph over youth and skill


Thats a good read WB, lots of info there and good analysis.  Smiley
  

“We either make ourselves miserable, or we make ourselves strong. The amount of work is the same.”
Back to top
WWW  
IP Logged
 
headcase
Global Forum Guide
Donor Member
*****
Offline


Former Youngest Person
in the World

Posts: 27317
Location: Ponsenby
Joined: Jul 9th, 2007
Gender: Male
Re: Above the snowline in the South Island
Reply #25 - Sep 9th, 2009 at 9:16pm
Print Post  
A lot has happened to the snow in the last couple of weeks. Overall the snow pack has stabilised and quietened down. Springtime is here. Warmer temperatures have started to turn the snowpack into a typical spring "isotherm" snowpack, and several melt/freeze cycles have stabilized the upper "layers". Strictly speaking an isothermal tending snowpack loses its individual layers and become a homogenous mass of snow from the top to the bottom. The surface softens and melts, generally during the day and freezes overnight forming that hard crust that we can walk on before lunch. The hardness and depth of crust depends of course on the weather in general. Many  factors such as clear or cloudy days and nights, overall temperatures, wind, angle of slope to the sun, and aspect of the slope, all combined, dictate just how much of a crust forms. As the crust melts and refreezes, so the total depth of snow warms and approaches zero degrees. The overall depth of snow lessens and the free water content of the snow increases. All this water in the snow tends to lubricate things, and afternoons and evenings in spring are usually the time when wet snow avalanches take place. That’s assuming the crust has melted during the morning as it mostly does in Springtime.

A crust of any kind is a good indication of a snowpack that is gaining stability, and a thick crust is a good indication of a slope that is safe to walk into, at least until that crust softens and melts.

Naturally hard crusts on steep slope make walking easier, but only with the right gear. Crampons and ice axe country. If you don’t have them, and don’t know how to use them safely, stick to the flattish stuff.

This will all seem pretty obvious to those that spend a lot of time in snow, but my comments are aimed at those that until now haven’t as yet had the opportunity to spent time in snow country , but plan to.


« Last Edit: Jul 11th, 2011 at 3:24pm by headcase »  

“We either make ourselves miserable, or we make ourselves strong. The amount of work is the same.”
Back to top
WWW  
IP Logged
 
headcase
Global Forum Guide
Donor Member
*****
Offline


Former Youngest Person
in the World

Posts: 27317
Location: Ponsenby
Joined: Jul 9th, 2007
Gender: Male
Re: Above the snowline in the South Island
Reply #26 - Sep 18th, 2009 at 8:45am
Print Post  
The snowpack has moved into typical "spring conditions' as can be expected at this time of year. Keep your eye out for cold clear nights, producing a good solid crust to walk over in the mornings, but which can soften quickly and leave you up to your thighs in soft wet snow after lunch.

High cloud covered skies in the night will hinder the snow pack freezing overnight, if at all, and produce soft conditions and a high wet snow avalanche hazard early in the day.  

The tragic death of a young climber/skier last weekend demonstrates the variety of alpine hazards that can face the unwary in snow and ice. The build up of wind driven snow and avalanche debris in creeks is now softening, and the surface layers are losing stability. The possibility of falling through the surface into a creek, whilst crossing snow bridges is now very real. Crossing any creek on a snow bridge require extreme caution, especially in steep gullies, where small hidden waterfalls may exist.. The result can be serious, finding oneself several meters below the surface standing or lying in a running creek is not recommended.  Wink
« Last Edit: Jul 11th, 2011 at 3:26pm by headcase »  

“We either make ourselves miserable, or we make ourselves strong. The amount of work is the same.”
Back to top
WWW  
IP Logged
 
headcase
Global Forum Guide
Donor Member
*****
Offline


Former Youngest Person
in the World

Posts: 27317
Location: Ponsenby
Joined: Jul 9th, 2007
Gender: Male
Re: Above the snowline in the South Island
Reply #27 - Sep 28th, 2009 at 6:48pm
Print Post  

Spring is the time of strong sun and melting snow. The greatest influences on the behaviour of the snow pack at this time are solar radiation, air temperature, wind,cloud cover and water.  The whole snow-pack slowly becomes isotherm, (the same temperature from bottom to top)  and goes through many melt freeze cycles until the snow disappears either in the form of running water, or water vapour, in a process called sublimation. This refers to water molecules passing from ice to water vapour without undergoing the melting process. Sublimation is an important process in the total energy balance of the snowpack, and plays a defining roll throughout the winter on the ever-changing snowpack stability.  
In Spring small snowfalls and storm cycles are followed by periods of fine and warmer weather. The snowpack is undergoing strong overall changes from layers that contain various individual types of snow crystals, bonding into a single homogeneous layer.  The avalanche hazard varies  daily, generally in 24 hour cycles, between night and day/ colder and warmer.

Wet snow avalanches
Wet slides occur when warm temperatures melt the surface snow layers and begin to saturate them with water. The water weakens the bonds between layers and avalanches often occur.  Wet avalanches move more slowly than dry avalanches but they can still be dangerous:
•      If temperatures have been above freezing for extended periods then wet avalanches will most likely occur
•      If you are sinking into wet snow up to your ankles or deeper , the snow is wet and prone to avalanche
•      If you squeeze a hand full of snow and it makes your glove wet or if water literally drips out of the snow, the snow may be prone to avalanche


The photo above shows typical spring conditions after a light snowfall. The first fine day brings strong warming of the new snow on sunny slopes. The new snow although not deep around the tops has started with a point form slide out of the rocky areas, widening as it rolls down over the open slopes and finally being channelled into a gully near the bottom. Although it started out only a few centimetres deep, this spring slide has amassed a depth of several meters in depth at the bottom. These kinds of slides are typically slow moving compared to dry slab avalanches /powder avalanche.

Below a close up of point formed damp/wet snow avalanche starting under a bluff. This is typical. Often started by a single stone falling from the cliff as the day and snow warms, or a single grain of snow which has “rolled” and started a chain effect.

Other wet snow avalanches fail on a plane or layer  and have a slab shape appearance  at the top,



Typical wet snow av. debris.  

Rainfall itself into spring snow is the super lub and will bring down everything that is ready to move and plenty that is not. It combines all the elements to produce wet snow avalanches. Water, added warmth, weight.

Spring time also brings good walking conditions if the surface is hard,  and generally safe conditions to travel as far as avalanche hazard is concerned. That is until the snow surface has softened to the point where one is starting to fall through it. At this time of day, it’s easier and safer to seek routes that take one onto open and snow free ridges. Don’t forget that not only do you have to be able to climb safely, but one must also be able to find the way home safely, so pick you routes that offer you a safe homeward journey in the evening. Late afternoons and evenings are the time in the spring when wet snow avalanches and glide cracks opening further and totally failing, are most common.


Walking over a lightly softened spring crust.

Glide cracks.
It’s common in spring to see wide cracks opening up in the snowpack on steep slopes or slopes that are convex near the top. The spring snow has a lot of water in it and the whole depth of snow may slowly start to slide, especially over grassy areas or surfaces  such as smooth rock.  These ground cacks open slowly over a period of days or even weeks, during spring melt/freeze cycles, which are normally night and day cycles.
The pic below illustrates well how a crack can be quite safe to move around during the morning or anytime the surface is still solid enough to carry your weight without sinking through for more than a few centimetres. This crack may have been open for several days of longer.


On a previous day someone has walked over it leaving footprints, and at some point there has been some wind which has blown a small amount of new or wind scoured snow into the crack.  Over a period of weeks the cracks can open up to several meters or tens of meters width, and still be perfectly safe to move around, as long as the surface is hard as you approach them. These Chamois certainly have no worries about the snowpack and are enjoying some of the spring growth behind the crack which the strong spring sun will be encouraging.

Occasionally the snow at base of the slope on which the crack is opening up, will fail, and the whole slope will come down. This only occurs if there is a huge amount of free water in the snow, usually running and lubricating the surface below the snowpack. If you can’t easily walk on the snow surface and it’s rotten to the point where you sink though to below your ankles, in extreme cases thighs, then it’s time to pick a safer route.


Above a failed Glide Crack, the thin layer of dirty white snow over grass or rock indicates that the snow has only recently failed. The strong solar radiation onto the grassy area would have otherwise melted the thin layer of remaining snow. The long shadows on the snow cast by the trees indicate the photo was made early morning or toward evening.  

Other Hazards.

Frozen surface layers.
The hard surface layer encountered mornings or during colder periods in spring brings other hazards.  Steep slopes can only be negotiated with a degree of safety on skis, if you are an experienced skier, but preferably with crampons and ice axe.  In even more extreme weather cycles the surface can become as slick as a mirror, as pictured below.  Rainfall or miniscule water particles blown onto the surface at around freezing point have produced a hard polished surface and under these conditions anyone venturing onto any slope without appropriate gear is risking life and limb. Often the slope may appear innocuous because it has a good run out at the bottom, but any rocks pocking out through the surface will become deadly as one slides over them at high speed.  The speeds attained during an uncontrollable slide are frightening and more than often fatal.

If you are a hunter come across something like the above,and wish to negotiate it safely, the only way is to seek another gentle(very) route around the hazard to a lower level where surface contitions may be different.


White out
Not confined to the spring, white out is a hazard that can be encountered anytime anywhere, but is particularly disorientating in a contrast free snowscape. Don’t climb into a white out if you are not very very familiar with the area.  Even then, one can become quickly disorientated.  Staying below thick cloud, mist and fog in a contrast rich environment is recommended. In the pic below there are actually five persons standing only about 20 m from the camera.



A contrast rich environment offers some visibility and waypoints to follow a route. However small scale hazards such as sharp changes in the terrain or small creeks may remain totally invisible even at very close range.  General direction can only be guessed at over longer distances and a slow change of bearing is inevitable unless one has an intimate knowledge of the way points.


Disorientation sets in rapidly if  there is no horizon and no points of reference, such as trees, rock faces, streams etc. The risk of wandering into dangerous terrain is very high, and often deadly. Even a small  fall into a creek bed can have serious consequences.

Below the snowline the visibility is better, but large scale disorientation is likely unless you are familiar and at home in the terrain.

Whiteouts due to snowfall will also make assessment of the avalanche risk more difficult in that one cannot see what is above and may in fact hide visable sign of strong winds and snow transport along the tops.. Some valleys are in in total wind-shade and all appears calm. Often the only indication of snow transport above you is the sounds of the storm roaring through the cliffs and bluff systems above.

A bracing experience. Smiley
Happy hunting.
« Last Edit: Jun 17th, 2014 at 6:17pm by headcase »  

“We either make ourselves miserable, or we make ourselves strong. The amount of work is the same.”
Back to top
WWW  
IP Logged
 
blackbunny
Donor Member
*****
Offline



Posts: 9907
Joined: Dec 13th, 2006
Re: Above the snowline in the South Island
Reply #28 - Jun 11th, 2010 at 5:14pm
Print Post  
Lots of great information in this thread Headcase. Thanks for taking the time to post it.  Cool Cool
  

Dear Noah,
We could have sworn you said the ark wasn't leaving till 5.
Sincerely, Unicorns
Back to top
 
IP Logged
 
Sikakila
Donor Member
*****
Offline


'Every day above ground..is
a good day!

Posts: 3867
Location: taranaki
Joined: Feb 8th, 2009
Gender: Male
Re: Above the snowline in the South Island
Reply #29 - Jun 11th, 2010 at 7:53pm
Print Post  
Holy smokes,never knew that much about snow.

Reason no. 67 why I dont hunt South Island tops.
  
Back to top
 
IP Logged
 
headcase
Global Forum Guide
Donor Member
*****
Offline


Former Youngest Person
in the World

Posts: 27317
Location: Ponsenby
Joined: Jul 9th, 2007
Gender: Male
Re: Above the snowline in the South Island
Reply #30 - Jul 2nd, 2010 at 5:06pm
Print Post  


02.07.2010
The Beginning of winter during the month of June got off to a good start with two good snowfalls from the southerly quarter. Snow is still lying on the ground to low levels, about 700m in the central south Island. At higher altitudes there is a good base, of a meter or more. The whole month remained overall cold so that snow has as yet remained fairly constant in depth. Only on the last days has strong solar radiation had its chance to work its magic in settling down the snowpack on sunny faces. However again, very cold temperatures will be hindering any real loss of snow depth at higher altitudes.
As a broad rule of thumb, it’s often said that a deep snowpack at the beginning of winter boads well and will be less problematic as the winter progresses.  And, a thin snowpack at the winter begin is less healthy and will tend to form unstable, weakly bonded layers within the thin snowpack.
Overall the risk of avalanche is moderate. No major slide has been observed and the layers are for the most part bonding well to each other. No natural avalanche occurrences have been reported as of today.  
Caution should still be exercised in slopes lee to the south west where new snow has accumulated due to wind transport.
The cold temperatures will be producing frost on the snow surface in shady places. These Hoar Frost crystals’ will form a weak bond between the present snow pack and any new snow that falls. Warm weather and wind may destroy them That remains to be seen.
Hoar Frost crystals growing over several days can reach depths of 6 inches and more in shady areas. They produce a very weak layer for the next snowfall to lie on.


  

“We either make ourselves miserable, or we make ourselves strong. The amount of work is the same.”
Back to top
WWW  
IP Logged
 
headcase
Global Forum Guide
Donor Member
*****
Offline


Former Youngest Person
in the World

Posts: 27317
Location: Ponsenby
Joined: Jul 9th, 2007
Gender: Male
Re: Above the snowline in the South Island
Reply #31 - Jul 18th, 2010 at 1:18pm
Print Post  
All the new snow and avalanche predictions warn of weakening bonds between the layers in the snowpack. There are also areas where surface hoar (frost) will fail when new snow arrives and settles on top of it. The surface hoar can be found in shady slopes.

Current reports can be read here.
http://www.avalanche.net.nz/index_aa.asp#mc


The danger is still low, because there is no "loading" on those weak bonds. That will change quickly though if we receive any new snow and especially if that new snowfall is accompanied by wind, which will carry the snow into lee slopes. Caution should be exercised if there is any new snow between now and your next trip into snowy regions.  

For the technically curious...

The bonds are weakening because of weeks of cold weather and calm clear nights chilling the surface layers. The snowpack is undergoing changes as it cools. The layers nearer the ground will remain more stable in temperature at around zero. The surface layers will be coldest. This produces what is called a temperature gradient in the snow.

This temperature gradient is morphing the snow grains.

Snow metamorphism

"Snow metamorphism refers to how snow crystals change once they are part of the snow pack, which affects how they bond or don't bond to other crystals based on their shape and density, which in turn influences the stability of the snow slope.  The major factors affecting snow metamorphism are temperatures within the snow pack, the temperature gradient between the bottom of the snow pack and the surface, the amount of moisture that is present, and pressure due to weight (Daffern 1983).  The process whereby the snow pack gains strength is called "sintering", which forms necks between grains of snow.  This typically occurs when metamorphism creates rounded grains due to a relatively low (flat) temperature gradient with regard to snow depth. In contrast, sintering does not occur when metamorphism creates faceted grains due to a relatively high (steep, or big temperature difference between base and surface) temperature gradient with regard to snow depth.  "

Surface Hoar
Heres a pic of surface hoar on the snow surface.

And this pic shows Surface Hoar that has been snowed on. The new snow on the top looks pretty stabil and well sintered, but its sitting on the surface hoar which is acting as a weak bridge between the top and bottom of the snowpack. The whole slope is ready to roll with enough disturbance, such as a hunter or skier moving over it.

Quote of the day.

"Three things we look for in the snowpack to determine the likelihood of an avalanche are poor STRUCTURE, lack of STRENGTH and available ENERGY. Currently, we’re lacking only an overlying slab of snow to provide the energy."
« Last Edit: Jul 18th, 2010 at 8:32pm by headcase »  

“We either make ourselves miserable, or we make ourselves strong. The amount of work is the same.”
Back to top
WWW  
IP Logged
 
headcase
Global Forum Guide
Donor Member
*****
Offline


Former Youngest Person
in the World

Posts: 27317
Location: Ponsenby
Joined: Jul 9th, 2007
Gender: Male
Re: Above the snowline in the South Island
Reply #32 - Sep 3rd, 2010 at 10:16am
Print Post  
And yet again.



Overall, watch the shady faces.  Cycles of sun and warmth have firmed up slopes with northern aspects (sunny), with a few exceptions where cross loading  and southerly winds have transported snow at higher altitudes.

Why is it that shady slopes are overalll the least stable? Ill be writing a short explanation of this in the coming week, so if you interested watch this space.  
« Last Edit: Jul 11th, 2011 at 3:41pm by headcase »  

“We either make ourselves miserable, or we make ourselves strong. The amount of work is the same.”
Back to top
WWW  
IP Logged
 
headcase
Global Forum Guide
Donor Member
*****
Offline


Former Youngest Person
in the World

Posts: 27317
Location: Ponsenby
Joined: Jul 9th, 2007
Gender: Male
Re: Above the snowline in the South Island
Reply #33 - Sep 25th, 2010 at 9:11am
Print Post  
This one is worth reading if you are looking for Tahr in the higher regions. Strong winds and snow have changed the avalanche danger for the worse. East facing slopes (morning sun) appear to be the most affected, but all aspects at altitude should be treated with caution.

There are reports of avalanches running down to the valley floor in the Mt Cook region. This is always a good indicator of big wind transport and cross loading at higher levels.


« Last Edit: Jul 11th, 2011 at 3:42pm by headcase »  

“We either make ourselves miserable, or we make ourselves strong. The amount of work is the same.”
Back to top
WWW  
IP Logged
 
headcase
Global Forum Guide
Donor Member
*****
Offline


Former Youngest Person
in the World

Posts: 27317
Location: Ponsenby
Joined: Jul 9th, 2007
Gender: Male
Re: Above the snowline in the South Island
Reply #34 - Jul 11th, 2011 at 3:43pm
Print Post  
Dont forget to visit

http://www.avalanche.net.nz/Forecasts/

if you a planning a backcountry trip this winter.  Smiley
  

“We either make ourselves miserable, or we make ourselves strong. The amount of work is the same.”
Back to top
WWW  
IP Logged
 
TG
Donor Member
*****
Offline



Posts: 419
Location: Wanaka
Joined: Dec 18th, 2007
Gender: Male
Re: Above the snowline in the South Island
Reply #35 - Jul 11th, 2011 at 9:19pm
Print Post  
headcase wrote on Jul 11th, 2011 at 3:43pm:
Dont forget to visit

http://www.avalanche.net.nz/Forecasts/

if you a planning a backcountry trip this winter.  Smiley


That new site is defintiely a step up
  
Back to top
 
IP Logged
 
headcase
Global Forum Guide
Donor Member
*****
Offline


Former Youngest Person
in the World

Posts: 27317
Location: Ponsenby
Joined: Jul 9th, 2007
Gender: Male
Re: Above the snowline in the South Island
Reply #36 - Jul 12th, 2011 at 1:31am
Print Post  
TG wrote on Jul 11th, 2011 at 9:19pm:
That new site is definitely a step up


Sure is, the new graphic way of displaying which slopes, at which height and aspect, have which level of danger is awesome. World class.. Perhaps better.  Cheesy

Over four meters of new snow has fallen over the last days on the Tasman Glacier, so there is definitely a big increase in snow depth the further one gets up against the main divide.
  

“We either make ourselves miserable, or we make ourselves strong. The amount of work is the same.”
Back to top
WWW  
IP Logged
 
HiTop
Forum Font
*****
Offline


Tops by dawn, a day in
heaven

Posts: 3166
Location: Canterbury
Joined: Apr 15th, 2007
Gender: Male
Re: Above the snowline in the South Island
Reply #37 - Jul 15th, 2011 at 9:31pm
Print Post  
That site is awesome!
Love the "avalanche danger 4. High/Don't go"

Very good work by those folks and should be effective also.

4m up the Tasman Shocked Shocked Shocked Shocked
  
Back to top
 
IP Logged
 
headcase
Global Forum Guide
Donor Member
*****
Offline


Former Youngest Person
in the World

Posts: 27317
Location: Ponsenby
Joined: Jul 9th, 2007
Gender: Male
Re: Above the snowline in the South Island
Reply #38 - Jul 16th, 2011 at 12:19pm
Print Post  


Winter 2011   
This is the first of a series of
short comments I’ll be making about the forces at work
in the backcountry this winter. Written to help the
curious understand what makes snow tick and expand
ones understanding of avalanches.

Here we find ourselves again at the beginning of a winter. It’s a time when many might hang up their hunting gear
and wait it out for more comfortable times when the
spring is upon us, but others see the winter backcountry
as a challenge and opportunity to hunt almost alone.

Our first big storm cycle has just passed, and covered the higher areas all over New Zealand in a blanket of snow. All the indicators are now on high that a significant avalanche danger exists. Anyone heading into the backcountry so
soon after the cessation of the storm cycle, should be aware of the danger in the area they choose to visit.
Time and weather will allow the snowpack to settle and
the situation will become clearer. There have been, in the past couple of days, several significant events recorded during avalanche control work on Southern and Northern
ski areas, so using that as an indicator, back country
travel at the moment should only be undertaken with caution.

As always, depending on the direction the storm was predominantly coming from, some areas received more of the white stuff, and others less. The media coverage would have us believe that huge amount fell everywhere but looking at the reports objectively, it’s apparent that higher areas toward the East received significantly less that similar areas close in to the Main divide. Ill stick to the South Island for the moment so as not to confuse the issue. Mt Cook village at 720m has 50cm of snow lying on the ground today, but Lake Tekapo Village, also 720 m and   only 20km distant as the crow flies, has no snow at all.

What does that have to do with the price of fish anyway? Well it tells us that some areas have started the season with a thick blanket of snow and others have only a thin layer, which will be quickly degraded by warm temperatures and sun. It’s pretty easy to gain an idea of how much snow is in any particular area by careful observation on a fine day. A thin snowpack will be quickly melted on the sunny faces and bare patches will be visible everywhere. The rocks and the detail in the terrain will be easily visible under the snow, tussock scrub and rock may stand out quite clearly if one looks carefully. Most ridges will be snow free as in the pic below



Or at a distance it may look similar to this.



At this time in the winter its early days, if you’re walking up ridges on a slopes as above, your hardly doing to get into trouble but what significance does a thin snow pack as pictured above have for the future.

First let’s look at what a deep early winter snowpack will look like as a comparison. At a distance it will resemble this picture, in the higher regions the terrain features are softened, few if any ridges are visible and the vegetation and rock are hidden by a thick blanket of snow.



  At a closer distance the slopes have a similar appearance as below.



Only the largest rocks and terrain features are visible under the snowpack. . Sunny faces and exposed ridges at lower altitudes may well lose their snow cover over time but the landscape is predominantly packed up like a bug in rug in a warm insulating snow cover. This insulation from the weather allows the ground temperature to remain at a pretty constant zero degrees through the whole winter. A significant fact, in influencing snowpack metamorphism as the winter progresses.

So here we have two different situations, a thin snowpack, and a thick snowpack, that may exist in the same general area at the same moment in time. They may only be a few kilometres apart, of just a range of mountains away. It might only be the difference between a shady wind sheltered place on one side of a ridge,  and a sunny face on the other. The combination of snow and terrain are many. 

Sun and shade, the snow pack will have cooler overall temperatures than the sunny face. 

What significance does a thin snowpack have against a thick snowpack at the beginning of the winter?

Easy one would think.  By any reasonable logic, just a little snow would be mean less avalanche danger as winter progresses, and a lot of snow would mean a big avalanche danger.
In fact, as general rule of thumb, a thin, marginal snowpack at this early time has the potential to produce an avalanche prone winter in that area, and a thick deep snowpack would tend toward a relatively stable and avalanche free winter. A gross generalisation of course, but nevertheless the overall tendency will be a stabile snowpack, if the snow is deep from the outset.
 
Why is this? The classic explanation is that a thin snow layer will be more influenced by low temperatures than a thick, deep layer. Low air temperatures and cold clear nights allow the snowpack to cool and what better time for low temperatures from early winter through to mid winter. Cold snowpack temperatures’ are relevant to how the stability of the snow layers increase or decrease.

The influence of temperature on the stability of the snowpack.
The snowpack is not uniform in temperature. Broadly speaking, at the beginning of winter, though to spring, the bottom snow layer(s), closest to the ground are warmer than the top layers, closer to the sky, and the influence of the weather. If we imagine that the ground, insulated from the cold nights and weather, by the snow itself, will stay at a relatively constant temperature, but, the surface of the snow, exposed to the clear night skies and cold weather will be much cooler.

The net effect is that at the bottom of the snowpack we have zero degrees and on the surface we have a minus temperature, for example - 10c after a clear cold night. If we dig a pit in the snowpack and measure the temperature range from top to bottom, say every 10cm in depth, we can plot a graph of the different temperatures at increasing depth, a temperature gradient or profile, a graph as pictured below.

This gradient in temperature effects the way the snow grains break down, or grow, at different levels in the snowpack. More to this process at a later date. At this point it’s sufficient to note there can be a strengthening or a weakening of the bonds between each grain of snow, and each layer, influenced by the steepness of the plotted temperate gradient, and the amount water vapour moving inside the snowpack.
Colder temperatures at the beginning of winter, influencing the snow to become loose and less stabile;;  and warmer temperatures in the snowpack influencing the snow crystals to break down and bond together. This is a pretty simple explanation and there are dozens of variable that will produce varying results, but in broad terms, any area that has a thin snowpack a the beginning of winter will be more avalanche prown as the winter progresses, and more snow accumulates over the poorly bonded cold lower layers.
Areas that start the winter with plenty of snow tend to settle and consolidate, the temperature gradient is flatter and the snow grains will tend to form better bonds to one another.  That also affects the way different layers, (every new snowfall produces a new layer) bond as well.



Here we see the various layers accumulated after many snowfalls. The various layers can be recorded, the size and type of snow crystals, the temperatures and the stability, and bonding of the layers. Many of those visible layers would have been deeper when the snow fell, but time, metamorphosis or the grains, and pressure as new snow builds up on the surface reduce the overall thickness of any one snowfall. (Storm cycle)
Whether the layers morph into a loose and unstable snowpack, or into a tightly knitted and bonded snowpack is highly dependent on the weather, depth of snow,  the temperature gradient, the terrain , and time,. Cold, open skies at night, and lack of sun all tend to cool the snowpack, producing overall unstable conditions until mid winter has passed. Warm weather = Warm winds, strong sun, or cloud cover at night all tend to warm the snowpack, producing a settling, and a stronger bonding of the layers,,  if the warm periods are interspaced with some colder temps. eg night and day with clear nights.  
What now happens after our first big snowfall is still in the hands of the Gods, but the weather over the next week or two will influence to a great extent the avalanche danger for the rest of the winter.


« Last Edit: Jul 18th, 2011 at 8:22pm by blackbunny »  

“We either make ourselves miserable, or we make ourselves strong. The amount of work is the same.”
Back to top
WWW  
IP Logged
 
headcase
Global Forum Guide
Donor Member
*****
Offline


Former Youngest Person
in the World

Posts: 27317
Location: Ponsenby
Joined: Jul 9th, 2007
Gender: Male
Re: Above the snowline in the South Island
Reply #39 - Jul 16th, 2011 at 12:23pm
Print Post  
HiTop wrote on Jul 15th, 2011 at 9:31pm:
That site is awesome!
Love the "avalanche danger 4. High/Don't go"

Very good work by those folks and should be effective also.

4m up the Tasman Shocked Shocked Shocked Shocked

Those folks have sure upped their game. Your right, its world class.
  

“We either make ourselves miserable, or we make ourselves strong. The amount of work is the same.”
Back to top
WWW  
IP Logged
 
headcase
Global Forum Guide
Donor Member
*****
Offline


Former Youngest Person
in the World

Posts: 27317
Location: Ponsenby
Joined: Jul 9th, 2007
Gender: Male
Re: Above the snowline in the South Island
Reply #40 - May 27th, 2012 at 9:29am
Print Post  
Its that time again. New snows already here in  most places around the tops, and new snow arriving with every front.

The Tahr Rut now underway, some will be venturing up to and well above the snowline.

Have a look at this when planning a trip to a specific area, and keep looking at it as the time comes to actually hunt that area.

its all here..

http://www.avalanche.net.nz
  

“We either make ourselves miserable, or we make ourselves strong. The amount of work is the same.”
Back to top
WWW  
IP Logged
 
headcase
Global Forum Guide
Donor Member
*****
Offline


Former Youngest Person
in the World

Posts: 27317
Location: Ponsenby
Joined: Jul 9th, 2007
Gender: Male
Re: Above the snowline in the South Island
Reply #41 - Jun 7th, 2012 at 9:14am
Print Post  
With big new snowfalls through the Southern Alps its worth having a good look at the area you are planning on going to this weekend and comparing it to the Avalanche Forecast. This is the first big snow of the year and things are uncertain as to what will happen. The first warming of the snow pack should bring some consolidation, but temperatures are to remain cold, and more snow is forecast, so safe conservative decisions are called for ..


Quote.. for the Arthers Pass area

Over a meter of new snow has fallen above 1200m in a short time (less than 24hrs). This will likely be sensitive until it has time to settle. Light
triggers such as a single person's weight could be sufficient to start avalanches in steep areas, so stick to lower angled terrain untill the new snow
has had time to settle.
  

“We either make ourselves miserable, or we make ourselves strong. The amount of work is the same.”
Back to top
WWW  
IP Logged
 
headcase
Global Forum Guide
Donor Member
*****
Offline


Former Youngest Person
in the World

Posts: 27317
Location: Ponsenby
Joined: Jul 9th, 2007
Gender: Male
Re: Above the snowline in the South Island
Reply #42 - Jun 8th, 2012 at 10:11am
Print Post  
Here we are, just 24 hours later, and there has been a significant change. High winds around the tops will have moved snow into the lee faces, and a significant avalanche danger will remain around the higher exposed areas/ridges.. .

Snow transport

The result.

A strong North Westerlies airflow over the alps has brought a significant warming, to zero and above in the lower regions and valleys. Even some sporadic rain showers. This warming will have an stabilizing effect on the snow, allowing it to settle and compact into a harder layer. This stabilisation process will continue especially as temperatures cool again.

BUT today still, as the snowpack warms and settles a significant moment will occur when the snow pack actually becomes more avalanche prone. It looses stability as it starts to settles. this moment may last for an hour or a day. that depends on , the weather trend.

This is a common occurrence after any snow storm cycle, and may be a simple raise in air temperature, a light rain shower, or the first rays of sun hitting a snow laden slope as the weather clears,

Today, I expect we will  observe  in the middle and higher regions some spontaneous avalanches as the warming process continues.
« Last Edit: Jun 9th, 2012 at 10:15am by headcase »  

“We either make ourselves miserable, or we make ourselves strong. The amount of work is the same.”
Back to top
WWW  
IP Logged
 
headcase
Global Forum Guide
Donor Member
*****
Offline


Former Youngest Person
in the World

Posts: 27317
Location: Ponsenby
Joined: Jul 9th, 2007
Gender: Male
Re: Above the snowline in the South Island
Reply #43 - Jun 19th, 2012 at 10:06am
Print Post  
  

“We either make ourselves miserable, or we make ourselves strong. The amount of work is the same.”
Back to top
WWW  
IP Logged
 
headcase
Global Forum Guide
Donor Member
*****
Offline


Former Youngest Person
in the World

Posts: 27317
Location: Ponsenby
Joined: Jul 9th, 2007
Gender: Male
Re: Above the snowline in the South Island
Reply #44 - Jun 25th, 2012 at 8:20am
Print Post  
For those planning a trip anywhere near/behind Mt Hutt, and Craigeburn Areas

http://www.avalanche.net.nz/Forecasts/region.asp?a=1

The Arrowsmith mountains have had upwards of 50cm of new snow in the past 24hrs at 2000 meters. Below 1700 meters the snowpack has
been rain soaked initially and now has up to 20cm of new snow on this interface. The June 20th crust interface remains a concern at higher
elevations although we expect a widespread natural avalanche cycle to have occurred around this layer. In the Mount Hutt Backcountry up to 35cm
of new snow is bonding to the old interface. Winds are picking up and wind slabs are forming on aspects lee to the westerly quarter.
  

“We either make ourselves miserable, or we make ourselves strong. The amount of work is the same.”
Back to top
WWW  
IP Logged
 
headcase
Global Forum Guide
Donor Member
*****
Offline


Former Youngest Person
in the World

Posts: 27317
Location: Ponsenby
Joined: Jul 9th, 2007
Gender: Male
Re: Above the snowline in the South Island
Reply #45 - Aug 10th, 2012 at 9:38am
Print Post  
For those Tahr hunting around the snowline, there is yet another storm cycle due this weekend and its worth a look at the avalanche forecast for the region your in.

the quote below for the Mt Cook region and the Two Thumbs (ready Macauley) is pretty typical of what to expect.

"Looking ahead it's likely that danger levels will
rise along with the accumulation of new snow.
Storm snow avalanching is possible on all
aspects but more likely on slopes lee to the
east. Plenty of surface hoar was observed in the
Mt Cook region today and it's likely to exist
around the two thumbs as well.
As the storm is
coming in without much wind initially this hoar
could well be preserved to become a problem
layer once buried. Back country travel is not
recommended over the next couple of days due
to poor visibilty compromising safe route finding
and caution is advised on the next fine day
thanks to the possibility of touchy avalanche
conditions if the surface hoar does turn out to be
a problem."

Surface hoar under new snow is a classic scenario for large avalanches, triggered by very little disturbance to the snowpack.



The frost crystals are quite delicate and will break suddenly under load, but at the same time they are just strong enough to carry the weight of a new snowfall until it reaches some depth. It takes just a little trigger for all the crystals to break en masse, and the total new snow sitting on top will slide of down the hill.
  

“We either make ourselves miserable, or we make ourselves strong. The amount of work is the same.”
Back to top
WWW  
IP Logged
 
headcase
Global Forum Guide
Donor Member
*****
Offline


Former Youngest Person
in the World

Posts: 27317
Location: Ponsenby
Joined: Jul 9th, 2007
Gender: Male
Re: Above the snowline in the South Island
Reply #46 - Jun 20th, 2013 at 5:22pm
Print Post  
Winter has once again arrived, with a vengeance in many parts of the country. I imagine the more alpine regions of the North Island are also taking a thrashing, but I'm going to comment on the area I'm familiar with, the high country, Central South Island.

The big snowfall started last night and continued through the whole day, accompanied by strong winds above 1000 asl from the SE quarter.

Some big snowfalls have been recorded. It would be fair to say that more than a meter of snow has fallen at higher levels, and in the lee of high ridges settling on North West quartered flanks,  there may be well several meters of new snow blown in.

The general rule of thumb by snowfalls of this quantity is that one doesn't even venture into the mountains at all until a warming and or settling cycle of weather has come to pass , and in all probability many natural avalanches have taken place, indicating a settling of the snow-pack, and a reduction in the extreme avalanche potential that we now have. Today and most certainly for a few days, and possibly a few weeks from today the danger will remain high. It all depends what the weather brings next over the coming weeks at the least..

One could expect large to very large avalanches to take place whether natural or triggered, some of them perhaps even running as large powder avalanches to the valley flow. Hence the old adage, 50cm of new snow, stay at home.

Time will tell.

In the meantime , if one is an alpine hunter, one can study  the recent avalanche advisory notices here, and start to follow them for your favorite area though the winter. By following your area , from the beginning of the winter, one can build a better mental picture of what is happening above the snow line, to your advantage at a later date.

http://www.avalanche.net.nz/

http://www.avalanche.net.nz/forecasts/detail.asp?m=8

And just as a bit of eye candy, here's avid that pretty much shows what can happen right now in the areas that have big accumulations of new snow.

http://www.youtube.com/watch?v=g227xto0N5Q&feature=share

http://www.youtube.com/watch?v=5BwsLhfH3TE

« Last Edit: Jun 22nd, 2013 at 1:38pm by headcase »  

“We either make ourselves miserable, or we make ourselves strong. The amount of work is the same.”
Back to top
WWW  
IP Logged
 
TJ
Online Forum Guide
Donor Member
Staff
*****
Offline


EBRG forever- Cher, cher
Bro

Posts: 12692
Location: hamilton
Joined: Nov 9th, 2006
Gender: Male
Re: Above the snowline in the South Island
Reply #47 - Jun 21st, 2013 at 9:07am
Print Post  
Yeah, nah. I will wait until spring thanks. Its obviously not the first one to come down that line
  
Back to top
 
IP Logged
 
headcase
Global Forum Guide
Donor Member
*****
Offline


Former Youngest Person
in the World

Posts: 27317
Location: Ponsenby
Joined: Jul 9th, 2007
Gender: Male
Re: Above the snowline in the South Island
Reply #48 - Jun 21st, 2013 at 12:10pm
Print Post  
Observation and continual reevaluation is everything TJ.
  

“We either make ourselves miserable, or we make ourselves strong. The amount of work is the same.”
Back to top
WWW  
IP Logged
 
headcase
Global Forum Guide
Donor Member
*****
Offline


Former Youngest Person
in the World

Posts: 27317
Location: Ponsenby
Joined: Jul 9th, 2007
Gender: Male
Re: Above the snowline in the South Island
Reply #49 - Apr 28th, 2014 at 5:38pm
Print Post  
A year goes by awfully fast these days.. first bigger snow on the tops today. A new winter is approaching.

First substantail pre winter snow fall in 2014, 28th April.

This may or may not form the base of our winter snow-pack 2014. Its early days and a strong NW flow could melt all of this right to the top in 24 hours.

On the other hand its been cool but sunny all day and its expected to drop below zero this evening, the 29th, so this snow will cool considerably overnight. Tekapo is around 700m and the tops around 2200-300m. Expect the air temperature to drop 0.5c for every 100m height difference. With a forecast -2c tonight at lake level, Id expect it to reach -10 thereabouts in the snow-pack this evening.  This is a significant temperature drop and may guarantee that the snow on the tops and in the shady faces will survive until the next snowfall.

What we are looking at here in this picture is the possible base, which will support all other snowfalls during the coming winter.




http://www.avalanche.net.nz/
« Last Edit: Apr 30th, 2014 at 8:59am by headcase »  

“We either make ourselves miserable, or we make ourselves strong. The amount of work is the same.”
Back to top
WWW  
IP Logged
 
headcase
Global Forum Guide
Donor Member
*****
Offline


Former Youngest Person
in the World

Posts: 27317
Location: Ponsenby
Joined: Jul 9th, 2007
Gender: Male
Re: Above the snowline in the South Island
Reply #50 - Jun 10th, 2015 at 9:27am
Print Post  
Forget about last winter 2014, it was pretty much a non event, snowfalls were sparse, localized to certain areas eg, "Southern Lakes", or "Central Plateau", and overall the winter short and mild.
"
So here we are at the doorstep to the winter 2015. First snowfalls have come that have any chance of remaining on the ground though this winter. Ive once again written a small piece around the snow situation in my local area. Mackenzei, Aoraki Mt Cook.

Why? because its only possible to give an accurate picture of the snow situation in a local area. Snowfalls , like the weather they are born of, vary hugely as do the preceding and anti ceding weather pattern. The differences from place to place, give hugely different results , often separated only by a single ridge-line or catchment area.

My objective is simply to talk about this area, which I can directly observe, in a effort to  raise awareness for the interested reader.

Everyone has to make their own personal decisions when venturing into the back country around snow and avalanche conditions, wherever that might be.


As posted in the hunting section after our largest snowfall in the Mackenzie up to date Winter 2015.

Big warm nor west blowing all last night and spasmodically through today. Will be a bit of snow melt going on, on the lower bits,  and plenty of wind transported snow in the higher regions .. The wind is picking up again, and the forecast is looking miserable for at least a couple more days..

This was taken a day back just before the weather turned to NorWest, only a hop away from where your talking about.

All the slopes in shade, which are south east facing, or shaded slopes after lunch, will be loaded with fresh wind blown snow around the tops, or saying the same thing in another way, any lee slopes, "wind shaded", from the North West Wind will be treacherous.

More snow and wind are forecast = 



There is a place to go to get a good idea of whats going on if you read the bulletin for your intended area carefully.

http://www.avalanche.net.nz/Forecasts/

Theres a new bulletin out for Aoraki Mt Cook which is very close  to the Godlay and usually similar in weather, (but not always).

The Mackauley tends to follow the weather patterns of the Rangitata more closely. (but not always, its the bloody weather..  Grin)

http://www.avalanche.net.nz/forecasts/region.asp?a=2

Here: http://www.avalanche.net.nz/forecasts/detail.asp?m=9
"Today(9/6/15) we have had 30mm of rain already in the MtCook Villiage this should equate to about 45 cm of snow above 2100 meters this snow is sitting on a generally stable snow pack that has been through a warm settling period early last week.
Around 2000 meters the snow pack has been rain soaked overnight so the snow will be wet and heavy makeing for unpleasent travel."


For the area your talking about.. ( my prognoses, based on something that should never be overlooked, its called "local knowledge")

As the weather is supposed to cool again and then start to snow again with high winds, the tendency for the next days will probably be, stabilization of the wet snow-pack in lower regions as it cools. Increase of avalanche danger in lee slopes at higher altitudes, due to fresh snow from the North West being blown in and deposited along ridges lines, and rivers running high.

Its all about timing, terrain, weather tendencies, and observation.. Grin Good luck.



  

“We either make ourselves miserable, or we make ourselves strong. The amount of work is the same.”
Back to top
WWW  
IP Logged
 
headcase
Global Forum Guide
Donor Member
*****
Offline


Former Youngest Person
in the World

Posts: 27317
Location: Ponsenby
Joined: Jul 9th, 2007
Gender: Male
Re: Above the snowline in the South Island
Reply #51 - Oct 31st, 2018 at 10:50pm
Print Post  
This is a time of the year when Tahr Hunters will be pushing up to the snow line in search of Tahr.  Even under the snowline when crossing gullies and terrain traps, the risk of an avalanche flowing down even below the snowline is present.. Stay safe, dont hang around in confined gullies.. stay on the ridges..

A sad reminder this morning at Mt Cook.

https://www.tvnz.co.nz/one-news/new-zealand/mountain-tragedy-jo-morgan-survives-...
  

“We either make ourselves miserable, or we make ourselves strong. The amount of work is the same.”
Back to top
WWW  
IP Logged
 
Page Index Toggle Pages: [1] 
Send TopicPrint
 

FishnHunt - New Zealands Famous Hunting and Fishing Forum Since 1995 » Powered by YaBB 2.6.11!
YaBB Forum Software © 2000-2021. All Rights Reserved.
Site Design By Alan Simmons - PRism and all rights are reserved from 1995 and onwards