Building the Colorado snowpack

[FrankZappa]

I agree with homer and most of what's been said so far but we're missing the other great Colorado boogieman: the wind. To be clear, I believe that we have much larger wind transport issues than other states.

True, True. There are lots of pieces to he puzzle though. This is just brain exercise for now. Maybe someone will learn some new stuff that might make 'em think twice before they get in over thier head.

[pechelman]

It's kinda like the term "permafrost" we've all heard.

fyi permafrost is soil that never thaws

edit: i beleive the proper term we're looking for is cryotic or frozen ground

[/small contribution]

[FrankZappa]

Thanks pelchman. We may need to get clairification from frozen on that 2nd one though. Maybe he's got a cousin by that handle.

Paging frozen....

frozen to the courtesy phone please...

[FrankZappa]

While we're talkin' about all these pieces to the puzzle, and buster seems to like to talk about humidity... I think this next one's important as well as intriguing.

Anybody want to tackle the hoar frost issue? You know... winters version of dew.

[Buster Highmen]

The wind affects the snowpack vapor gradient as well. Especially LB's hot wind.

[lemon boy]

buster would like to talk about humidity, it's actually humid where he lives

As for tackling surface hoar I'll take a high wind and warm sunny temps for 1000 Alex.

perhaps it'd be better to keep our variables somewhat bounded by Colorado reality, if hypothetical reality with respect to things like humidity, temps, winds, snowfall totals and frequency.

[FrankZappa]

Are you saying there's no such thing as surface hoar in Colo. LB?

Check these:
(I assume this was somewhere around CB since it's from thier avy website)


I dug this one up on Wolf Creek back in Jan 2001

[lemon boy]

absolutely not (not sure why you think I was*)



*perhaps it was my tackling part which was meant to say that IMVHO high winds and sunny warm temps would/could/should dispatch a SH layer prior to burial

[FrankZappa]

Sorry LB, my fault. I got caught by the "keep our variables somewhat bounded by Colorado reality" part I guess.

Lots of Colo doesn't get the wind though like the front range does. And I've skied the SF late in the day when it's been sunny out (but not exactly "warm" - but not really cold either)


Just to add to the above buried layer I put up, It boke easy, and a lil' later when we moved on to another hill, we watched these folks & the line and grouping they took. (they were on the same mound of dirt as the pit but around it maybe a half mile). Poor travel technique IMO.

[lemon boy]

well I definitely think that if we're building the perfect colorado snowpack we'll leave both them fucking hoars out of the whole shebang.

[Hacksaw]

Poor travel technique IMO.

That kind of photo gives me the "hebiegibies."

[FrankZappa]

'Bout time you showed up!

Got $0.02?

[Buster Highmen]

As for tackling surface hoar I'll take a high wind and warm sunny temps for 1000 Alex.

I thought surface hoar was a function of cold, dry night air drawing the moisture up out of the snow as well as a dry sunny day that generates vapor in the subsurface snowpack.

perhaps it'd be better to keep our variables somewhat bounded by Colorado reality, if hypothetical reality with respect to things like humidity, temps, winds, snowfall totals and frequency.

Reality? How much does that cost? Where can I get some?

[Hacksaw]

'Bout time you showed up!

Got $0.02?

Sorry Tom,

I'm running out the door in a second. I'll try and post something later.

Cheers,
Halsted

[FrankZappa]

well I definitely think that if we're building the perfect colorado snowpack we'll leave both them fucking hoars out of the whole shebang.

Between this and talk of wind, someone's gonna get all this confused with hookers and blow.


Now, back to our regularly scheduled program...

[FrankZappa]

I sent an E-mail over to CAIC a couple days ago to see if anyone there wanted to contribute to this. Doesn't sound like they had too much time to deal with it for now but here it is.
Maybe when Halsted gets back he'll elaborate or give us some more fat to chew on. (Bacon fat please).
Thanks Spencer

9/28 AM.

Tom,

I've only glanced at this thread. So, with no knowledge of where the
discussion is, a couple pennies:
* Staying Alive in Avalanche Terrain pp117-125 has a great explanation of
faceting and depth hoar formation. Fig 5-7, on p 121, has some of the
answers
* Temperature gradient is temperature difference/distance
* Change the air temp. Warmer air (similar to ground temp) reduces
temperature gradient--less change over distance
* Change snow depth. Thicker snowpack reduces temperature gradient--greater
distance "spreads" the temeprature difference out.
* So good early season for CO would be lots of snow and mild
temperatures--think the begining of last season in the Front Range and
Summit Co

There's a nickle for you.

Spencer

[Hacksaw]

I sent an E-mail over to CAIC a couple days ago to see if anyone there wanted to contribute to this. Doesn't sound like they had too much time to deal with it for now but here it is.
Maybe when Halsted gets back he'll elaborate or give us some more fat to chew on. (Bacon fat please).
Thanks Spencer

9/28 AM.

Tom,

I'm down in T-ride for the ISSW (major snow nerds conference) I have limited time an access to the web.

What Spencer listed from Tremper's book, can answer a lot of the misconceptions that folks might have about our wonderful Colorado snowpack.

When I get home I'll try and dig-out (sorry bad pun ) thiis old chart that compairs the Continental, Intermountain and Maritime snowpacks. The differences are VERY major, and present their own good and bad aspects.

Cheers,
Halsted

[goldenboy]

So I was thinking about some things last week...

Iski made a good point about the ground in Sept. still being warm. So, let's say the ground temp right now is still 42, and overnight lows are 22 (reasonable on high snow covered areas right now, I think). That would be comparable to lows around 12 once the ground is at its' normal wintertime temp of around 32. Therefore, excluding other variables like hours of daylight and humidity, the foot or two we have now (at least on high n faces) would be the same as having a foot or two in late nov. I think that we can all agree that a foot or two in late nov. would be a very bad thing and would lead to a pretty rotten snowpack.

Right now, I don't like what I'm seeing at all. We still have snow here at my house (9500') in the shade. There is still snow even on s faces up high. Some snow, but not much, is in the forecast this week down to 9 or 10,000'. I don't see the sept. snow melting before "real winter" arrives, barring a rainstorm that goes high. Sadly, I think there's a good chance of the snowpack being pretty rotten near the ground this winter. Then we can start a new thread about "bridging"

Hacksaw or another avalanche pro- feel free to rip me a new one if I'm way off here.

[Z]

This thread was good read, thanks. I've got lots to learn about our snowpack.

Don't really have anything to add as it seems I rely more on terrain/consequences/abilities than anything else....Definitely need to dig some more pits with people who know whats up....

[Buster Highmen]

This thread was good read, thanks. I've got lots to learn about our snowpack.

Don't really have anything to add as it seems I rely more on terrain/consequences/abilities than anything else....Definitely need to dig some more pits with people who know whats up....

Honestly, I think terrain choice is the best avie avoidance scheme ever.

[FrankZappa]

terrain choice is the best avie avoidance scheme ever

Thats true, but a certain amount of the same logic can be applied to driving a car. If you don't know how it operates you're probably gonna not enjoy the ride, especially when all goes to hell and you may crash and worse you may die. If you take the time & figure out the operation your knowledge and confidence level should give you the ability to decide whats a good choice & whats not.

So it seems there are several ways to look/hope for what we're in for in the coming months (or any other year).
1) From a bettin' mans standpoint, it'll more than likely be the typical scary crap. Thats just the way the odds stack up here in Colo. generally.
2) From the optimists perspective, all you can do is hope Ullr, Sol & their buddies are good to us & deliver in the best way they can.
3) From the pessimists point of view... Well that kinda goes along the lines of the Gamblin mans
and I'm sure there are others...

As for what we usually get which is that damn crap at the bottom, I personally like (& hope for) that big windy, heavy storm say mid Nov. to Jan. that comes in and makes almost everything in sight load up and slide, or as I call it "Flushes the toilet." Then we can feel a lot safer about some of those boogie men on stilts out there.

[FrankZappa]

I woke up before the crack of shit thinkin' about three more TG related things.

• Terrain - in a very Local sense
• Vegitation
• Whumphing

Some of the biggest whumphing I've run across seems to have happened (or have been triggered) where a combination of these things occur. And, as I recall, in quite a few of the avy reports I've read about and looked at, many times the crown fractures from one of these randomly placed features to another to another and so on.

Note that what I'm refering to as "local terrain" are faetures that extend above the general plane of the ground such as rocks, boulders or maybe deadfall...
And in terms of vegitation in this case generally I'm addressing the "lower level" stuff like grasses and bushes - lets say thigh high and lower.

So here's some of the assiciated questions:
What effects do vegitation and the local terain play in the pack formation?
What going on around these features: Is there a TG and related transformation? - or something else?
At what point does an "anchor" like feature do more harm than good? - or vise a versa?
Is there any relation that might make one feature "better" than another? - ie. A grassy slope vs. one covered with knee high willows.
Whats up with whumphing? Early season (in the base pack) I'd bet it's usually a TG layer letting go but what about later in the mid & upper pack.

[FrankZappa]

So, with what I just put up about features like vegitation, and some of the stuff that goldenboy has been seeing out there:

So I was thinking about some things last week...

Iski made a good point about the ground in Sept. still being warm. So, let's say the ground temp right now is still 42, and overnight lows are 22 (reasonable on high snow covered areas right now, I think). That would be comparable to lows around 12 once the ground is at its' normal wintertime temp of around 32. Therefore, excluding other variables like hours of daylight and humidity, the foot or two we have now (at least on high n faces) would be the same as having a foot or two in late nov. I think that we can all agree that a foot or two in late nov. would be a very bad thing and would lead to a pretty rotten snowpack.

Right now, I don't like what I'm seeing at all. We still have snow here at my house (9500') in the shade. There is still snow even on s faces up high. Some snow, but not much, is in the forecast this week down to 9 or 10,000'. I don't see the sept. snow melting before "real winter" arrives, barring a rainstorm that goes high. Sadly, I think there's a good chance of the snowpack being pretty rotten near the ground this winter. Then we can start a new thread about "bridging"

Hacksaw or another avalanche pro- feel free to rip me a new one if I'm way off here.

Maybe, (I'm speaking in terms of the vegitation here), the early storm systems can play a bit of a good roll in the pack formation. Here's what I mean: If the snow we got was enough to flatten some of the vegitation, don't you think that could help by at least making the TG layer more consistant and less irratic in depth thereby reducing some things such as trigger points?

[FrankZappa]

Just wanted to link in a little of what I'm thinking in terms of the weak points caused by vegitation in post above.

Trap Park
January 1, 2006
7 snowmobilers caught, 5 partly buried, 2 buried and killed


Look at where the crown fractured from tree to tree to tree...

The avalanche fractured just over 3 feet deep to the ground with a maximum depth of 4.5 feet. The slab was remarkably consistent and strong but unfortunately it was perched above 8 inches of weak, faceted, sugar-snow grains.

This from the CAIC report page for 2005/06

[FrankZappa]

I'll link this one too
From the same 2005/06 CAIC page

Berthoud Pass
November 6, 2005
1 backcountry snowboarder caught, buried and killed

Fracture line on Mines Peak 1. The depth in this spot is 2 feet. The top 4 inches is soft wind-affected snow. The middle 14 inches is very hard wind slab that was created by the weekend's new snow and strong winds. The bottom 6 inches is faceted sugar-like snow that first fell earlier in October. These grains had become loose and cohessionless.