Building the Colorado snowpack

**gretch6364** · 10-23-2006, 07:16 PM

How is this recent storm going to affect the stability of the Front Range Snow Pack this year??? Is it going to be trouble??

**FiveLarge** · 10-24-2006, 12:32 AM

Originally Posted by gretch6364

How is this recent storm going to affect the stability of the Front Range Snow Pack this year??? Is it going to be trouble??

For discussion sake, what in particular would make you think this recent storm is going to be trouble? (Think about the factors that enhance/degrade stability.) And for a reference point, I know you're new here, but you have said you've done your avy I certification, right? Or am I confusing you with someone else?

**Joey Joe Joe Junior Shabadoo** · 10-24-2006, 08:07 AM

^^^ Well my name isn't gretch but what the hell. And keep in mind I am talking generally here as I haven't had a chance to ski in the Front Range this year yet. The most recent storm brought a lot of loading in a short period of time(think Iski's 30in in 24 hours). This kind of loading is always going be potentially hazardous as snowpacks generally like incremental loading so they have time to adjust to the new snow. This may be one reason the CAIC is reporting slides over the weekend in the tenmile range and one north of Berthoud. The other contributing factor is the wind that brought in these storms which causes everyones favorite, windloading. So in the short term the new snow could be potentially hazardous as it is a big stress to the snowpack. As the snowpack stabilizes and adjusts to the new load the added depth is usually a good thing. The hazards from the windloading may persist for longer though.

**lemon boy** · 10-24-2006, 09:16 AM

JJJJS-

pretty sure he's asking about the longer term issues associated with so much early season snow. And like SPT, I'm betting that he already has a pet theory based on his question.

**Joey Joe Joe Junior Shabadoo** · 10-24-2006, 09:22 AM

Yeah I wasn't sure whether he was thinking long or short term. so whats the pet theory SPT?

**lemon boy** · 10-24-2006, 09:23 AM

that's what we're trying to draw it out of gretch

socratic method and all dat shit.

**homerjay** · 10-24-2006, 09:59 AM

These warm temps are helping out a bit as far as consolidation v. faceting. However, it's fucking freezing at night. I'm sure there's a point where it could go either way...what is that point?

**smitchell333** · 10-24-2006, 10:50 AM

One of the main concerns with what we've got is over time it will rot at the bottom due to Temperature gradient/faceting unless we get enough to negate the effect.

For example lets say on average there is probably about 20" on the ground. Thats about 50 cm. Strong temperature gradient and the resulting significant vapor transport that leads to faceting is defined as 1 deg C/10cm. So if its colder than -5C (23F) at any time there is significant faceting in the snowpack where the depth is 20"(50CM).

At Berthoud last night it looks like the low was 17.7F (-8C) - so the effect is significantly underway. On a tour yesterday to about 12.5K' I found a significantly inverted pack at/abobe treeline - with wind slab starting to form on the top and light snow in the middle and beginnings of facets at the bottom. Got some mild whummphing already

Good skiing for Oct though - pow esp below treeline.

Pray for more snow b/c if we can get to 50-60" then the effect is greatly reduced as the temps dont consistently get low enough.

**gretch6364** · 10-24-2006, 12:07 PM

I do not have any theories in mind. If I did I would have shared to stimulate conversation. I going to the free avy training tonight actually, so I am new to this whole thing. I want to take a CPR class ASAP as well and of course have all the needed equipment. I want to know as much as possible before I risk my own life or anyone else skiing with me. I have also met a couple veterns as well as some maggots that have much experience to show me around.

I really was looking for answers on the snow pack and had heard about some issues with it getting warmer and the snow not melting..maybe becoming sugary???

Just looking for more knowledge...thanks

**lemon boy** · 10-24-2006, 12:18 PM

hacksaw puts on a great show even if he does say so himself sometimes

I think you'll find the basic answers to your question in this thread especially closer to the start (or smitchell's post just above). The biggest thing IMM (and discussed previously in depth) is everything turning to sugar if we don't build up a decent base. The sugar snow creation would be if it stays cold + shallow, not if it warms up (the discussion early on about warming was in the hopes of just melting off the first snows so they're a non-factor).

And I dunno if anyone noticed but Wed-Thursday is supposed to be holy windy (and snowy).

**AltaPowderDaze** · 10-24-2006, 12:27 PM

Originally Posted by gretch6364

I really was looking for answers on the snow pack and had heard about some issues with it getting warmer and the snow not melting..maybe becoming sugary???

Just looking for more knowledge...thanks

i don't think the snow melting off is even an option now. you guys are going to have to make due with what you've got, as are we. best hope would be for stromy weather over a perior of a few weeks that just drops 3-12" right side up a storm. once the pack gets about 4 feet deep the faceting at the bottom of the pack begins to retard and you start looking at your next midpack layers. lots of heavy snow in a short period or windloading may reactivate those deeper layers.

***although colorado deals with more full depth releases than utah does.

**FiveLarge** · 10-24-2006, 07:49 PM

all - good thoughts

gretch - I think these others have put out some good responses to your q.

Mostly repeating what's been said, but in short, I think a big storm like what we got, long term, is good. As a generalization a deeper pack is a more stable pack...longer term, for reasons smitchell and APD get at. JJJS's assessment of short term issues is spot on...fast/deep loading is NOT good for immediate stability.

Warm temps also generally help to stabilize the pack...as long as the warmup isn't too severe/fast. This is most evident in the spring time, where the pack goes to isothermal and the layers cohese into one. (also the time when we get the most wet-loose slides and point releases). But, still watch those warmer temps...they can also create a freeze crust, which can be a great bed surface for the next layer.

Kudos for going to the presentation tonight, and for wanting to get the CPR class...good attitude of safety for self and for your partners. Definitely suggest going for the full-blown avy level 1...Hacksaw just can't cover in one night what they do in 2 nights of classroom and a full day in the field. (I realize some tentative FOBP avy field days are in the works...I wouldn't let that stop me from doing the level 1 class). Some other suggestions: pick up some good avy books and read some more. Read the accident reports on the CAIC website from years past...definitely lessons to be learned. Once the CAIC starts issuing daily forecasts, read them everyday. Get out there and practice with your beacon, and practice with pits and tests...all the reading/classroom education is an essential...but you've got to put it to practice.

And, this isn't coming from the guru...these are all good reminders for me as well...always something to learn, always skills to improve.

**HikeforTurns** · 10-25-2006, 07:01 AM

chance of snow,
For the Montezuma Ski Area:

today 90% chance 5-9"

tonight 90% chance 8-12"

tommorow 80% chance 3-5"

No.....way.......I.....can....ditch work................thursday...............ARRRRRR RRRGHHHHHHHH!!!

**gretch6364** · 10-26-2006, 11:02 AM

Well...Breck is reporting 24 inches of fresh snow at mid mountain...and my parents are in town from the Burgh for the weekend...what great timing!!!

Oh well...hopefully we get the right weather to make it stable...it is pretty dangerous right now...ten slides last week......everyone be careful these next couple days...I foresee trouble

**FrankZappa** · 10-26-2006, 11:16 AM

Choose terrain choice wisely and use proper travel techniques. Backcountry can be done at any time, you just need to watch/know where you are and what you are doing at all times, and really be evaluating your risk assessment.

Sometimes (most times actually) you just can't turn 'em (or climb) on certain hills. Taking a detour/ change of plans always needs to be an option.

**FiveLarge** · 10-26-2006, 05:12 PM

Originally Posted by gretch6364

Well...Breck is reporting 24 inches of fresh snow at mid mountain...and my parents are in town from the Burgh for the weekend...what great timing!!!

Oh well...hopefully we get the right weather to make it stable...it is pretty dangerous right now...ten slides last week......everyone be careful these next couple days...I foresee trouble

10 slides is nothing...that was from 1 forecaster within a portion of one range. Once the CAIC is up and running fully, you'll see days with hundreds of slides reported...

That being said...yes, we've had some significant loading (lots of snow, and fairly high water content) in the past 24 hours, so danger is elevated...

**gretch6364** · 10-26-2006, 05:31 PM

I have not seen this snow personally, but word has it that it is rather wet and heavy even at higher elevations. Is this good or bad for the snow pack...just curious??

I am not even sure what is safer...heavy or light snow?? I would think the heavier snow would make for a stronger base...but I am just guessing

I am also talking long term not short term...as in after another week or so will it be safer...and then even longer term...will it be better for a base in like December and January??

I would think heavy snow would consolidate faster and create better coverage over rocks and what not as it should pack tightly...thanks again....

lastly...I am sure this may have been mentioned already...but does anyone have any suggested reading related to avy's that I could pick up in a denver book store??

**FrankZappa** · 10-26-2006, 05:49 PM

Originally Posted by gretch6364

I have not seen this snow personally, but word has it that it is rather wet and heavy even at higher elevations. Is this good or bad for the snow pack...just curious??

I am not even sure what is safer...heavy or light snow?? I would think the heavier snow would make for a stronger base...but I am just guessing

I am also talking long term not short term...as in after another week or so will it be safer...and then even longer term...will it be better for a base in like December and January??

I would think heavy snow would consolidate faster and create better coverage over rocks and what not as it should pack tightly...thanks again....

lastly...I am sure this may have been mentioned already...but does anyone have any suggested reading related to avy's that I could pick up in a denver book store??

It's a constantly changing thing. Lots of things effect it, and in different ways, some good, some not... wind, temps, sun (or none), more snow, less snow, rain,...

For reading, my local library has lots of these or will bring them in. Here's Silverton Avy school's suggested reading.

**DanKo** · 10-26-2006, 07:48 PM

"Snow Sense" is the most-accessible read.

**smitchell333** · 10-27-2006, 11:03 AM

Originally Posted by gretch6364

I have not seen this snow personally, but word has it that it is rather wet and heavy even at higher elevations. Is this good or bad for the snow pack...just curious??

I am not even sure what is safer...heavy or light snow?? I would think the heavier snow would make for a stronger base...but I am just guessing

I am also talking long term not short term...as in after another week or so will it be safer...and then even longer term...will it be better for a base in like December and January??

I would think heavy snow would consolidate faster and create better coverage over rocks and what not as it should pack tightly...thanks again....

lastly...I am sure this may have been mentioned already...but does anyone have any suggested reading related to avy's that I could pick up in a denver book store??

Hopefully all this is true. I was out yesterday and can say it was heavy - made for higher danger as it rested on a shallow and mostly rotten snowpack. But I think once it settles down it should make a decent base as it will keep more of its depth than lighter snow.

Cold temps at night will still tend to rot out shallower areas, but the effect will be reduced anywhere the pack is deeper.

One more of these and we'll really be talking.

**Rontele** · 10-27-2006, 10:04 PM

Interesting article in the Rocky Mountain News today about the recent storm, El Nino, and weather trends for the rest of the season. While I don't always tend to buy long term forecasts, especially in how the mass media covers them, there were some interesting nuggets.

The meterologist said that the wet fall should continue through November with many of these similar, spring type upslope storms. Cannot complain about that as it will help to build the base. But then said that there will be a drying trend through the winter

with the snows returning heavily in the spring (March, April, May).

As has been posted throughout this thread, iskibc's theory about November being crucial, I believe continues to be key. But let us say, assuming this story in the paper turns out to be true, then isn't it all kind of moot if Dec and Jan are cold and dry? Won't the same surface hoar > depth hoar issues just come later in the season, perhaps at higher cost as people try for bigger lines as the "real" winter sets in? The fervor on the board with this past storm has been the highest since I have joined TGR. It gets me worried because I have a very very very low risk threshold and worry that others do not. Just be safe out there, pay attention to threads such as this, which are invaluable as a clearinghouse of information regarding the snowpack, bring your avy gear, be safe and continue the stoke.

The last three sentences were officially brought to you by the bottle of Pinot Noir I downed at dinner

**smitchell333** · 10-27-2006, 10:26 PM

Originally Posted by Rontele

As has been posted throughout this thread, iskibc's theory about November being crucial, I believe continues to be key. But let us say, assuming this story in the paper turns out to be true, then isn't it all kind of moot if Dec and Jan are cold and dry? Won't the same surface hoar > depth hoar issues just come later in the season, perhaps at higher cost as people try for bigger lines as the "real" winter sets in?

Yes possibly that is a concern - but the good thing (potentially) about what we've gotten and if it continues into Nov is that the powers of Tempurature Gradient are reduced with the more depth we have - and the result is the retardation of the depth hoar development.

Surface hoar and mid pack layers another story, but things are a lot different w/o all that facets at the bottom.

**FrankZappa** · 10-30-2006, 11:57 AM

Originally Posted by Rontele

The meterologist said that the wet fall should continue through November with many of these similar, spring type upslope storms. Cannot complain about that as it will help to build the base. But then said that there will be a drying trend through the winter

with the snows returning heavily in the spring (March, April, May).

As has been posted throughout this thread, iskibc's theory about November being crucial, I believe continues to be key. But let us say, assuming this story in the paper turns out to be true, then isn't it all kind of moot if Dec and Jan are cold and dry? Won't the same surface hoar > depth hoar issues just come later in the season, perhaps at higher cost as people try for bigger lines as the "real" winter sets in? The fervor on the board with this past storm has been the highest since I have joined TGR. It gets me worried because I have a very very very low risk threshold and worry that others do not. Just be safe out there, pay attention to threads such as this, which are invaluable as a clearinghouse of information regarding the snowpack, bring your avy gear, be safe and continue the stoke.

The last three sentences were officially brought to you by the bottle of Pinot Noir I downed at dinner

As long as I can remember, a drying trend mid winter is very common. I would say more common than not. Sometimes it's short lived and sometimes I can remember it lasting six weeks with hardly any new. It can be a time when things get considerably stable and many good lines can be had or it can be the worst case senario. But how stable that time is depends on a lot of things but mostly I think on how the earlier pack set up. If it's shallow the TG gets worse and we better watch out (I've had some of the worst runs in my life skiing Wolf Creek BC mid winter when it's 3 to 4 ft of suger with only 8" of fresh(er) on top that you constantly busted through). But if it's deep and bonded well then things can be good (Silverton area was nuts a couple winters ago during this cycle - tracks on almost everything in site). Recycled pow is great, smooth and fast.

As for the upslope conditions (this is all East slope conditions I'm talkin' about here), my opinion is they only (well at least 90% of the time) effect the foothills and plains. Especialy fall and winter. Spring systems sometimes have enough energy to push them up to the divide and can produce good amounts - but thats been just my observation. So unless you're planning on skiing Eldora or La Veta pass I don't put much faith in them until spring for helping with our snowpack. - as they tend to be at lower elevations and what they produce probably will melt away or be in areas where there isn't enough of a pack to do much with, at least not longer term.

So, I'll hope for what smitchell333 said about getting the pack deep before Dec. so as to reduce the TG. - but like as was said before it needs to keep building in a consistent manner.

As for the "bottle of Pinot Noir" sponcership section, I suggest only assessments on site when you're out in the selected BC as being your main system of risk management.

**grskier** · 10-30-2006, 09:25 PM

Originally Posted by gretch6364

I have not seen this snow personally, but word has it that it is rather wet and heavy even at higher elevations. Is this good or bad for the snow pack...just curious??

I am not even sure what is safer...heavy or light snow?? I would think the heavier snow would make for a stronger base...but I am just guessing

I am also talking long term not short term...as in after another week or so will it be safer...and then even longer term...will it be better for a base in like December and January??

I would think heavy snow would consolidate faster and create better coverage over rocks and what not as it should pack tightly...thanks again....

lastly...I am sure this may have been mentioned already...but does anyone have any suggested reading related to avy's that I could pick up in a denver book store??

Gretch, I'm in the same boat as you... I just picked up Snow Sense a couple of weeks ago at the REI in Boulder. I have since read it like 3 times, great book. I plan on getting a few more as well in the coming months. This is the thread I started: http://www.tetongravity.com/forums/s...ad.php?t=62496
Thanks for asking these questions, I've had many of the same.

All that being said, should we be concerned about the drier week it seems we'll have now? I know that the wind can/will produce loading on a possible surface that has had some freeze thaw, the sun can help bond the layers, but the clear cold nights will promote faceting.

In regards to what Zappa said, isn't this similar to how last season started, albeit almost a month earlier, given we continue to get snow in November and assuming that December and January are a bit drier.

**FrankZappa** · 10-31-2006, 11:54 AM

Originally Posted by grskier

All that being said, should we be concerned about the drier week it seems we'll have now? I know that the wind can/will produce loading on a possible surface that has had some freeze thaw, the sun can help bond the layers, but the clear cold nights will promote faceting.

As far as the intermixed drier weeks go I think we'll always have these... It is Colorado after all.

We need to take notes or remember these events (and others) throughout the season and keep tabs on what they're doing as they become buried. Sun crusts can vary greatly too between elevations and aspects, so think about these too.

Depending on where we choose to tour, the wind and loading and thier effects can vary greatly. We need to be aware of this and choose our routes wisely. The differences between above timberline and below I think are the most notable. I find myself below in the trees most of the time, but I still have to assess changes there too - like coming into a chute or alley, and keeping an eye out for terrain traps. I think many a deadly slide/sluffs happen on small innocent looking slopes, especially those with a trap at the bottom.

Here's an observant comment from a thread today about our typical hills just about anywhere along the windward side of the divide.

Originally Posted by powstash

Do the ridgelines in Colorado ever hold snow? Seems like from most TR's one could do tennis shoes on ridges all winter long in CO.

and a pic showing a sample of the transport to go along with it.

10" - 20" of fresh (and what has been described as wet and heavy) snow just fell here a couple days prior to when this pic was taken.
Where do you suppose all that snow is now?

Here's a shot of the east side of the divide looking south in a north/south drainage (or close to right angles from the prevailing winds) just over the ridge from the famous Grizzly couloir south of Indy pass. Look at the loading on that very inviting face with the slide on it. I would bet the west (windward) side of this ridge is almost completely bare. I had just been up there three weeks prior and the very same face had slid. That's probably a 6' - 10' crown. That's a lot of loading going on in just a few weeks and the bed surface may be the same.

Where directly across the gulch on the next windward ridge we had huge hardslab conditions in the lower faces (which also look to be very inviting - but spooked me when I got close enough to the edge that I could feel the hardness under foot and hear the hollow "drum" sound. If I'm correct, hard slabs can be easily triggered from pretty big distances away - like down in the bottom of this gully - and that part keeps my attention. Plus the idea of huge hard blocks of debris running loose doesn't sound too fun either.
And again in the upper left we can see the wind scoured signs of almost complete transport over the ridge to be deposited in the next lee area.

I did get into that next gulch and the cornice, face and avy prone deposition zone was very impressive. 20' - 40' cornice x almost a mile long/wide slide path to the bottom and hundreds of feet up the other side.

Originally Posted by grskier

In regards to what Zappa said, isn't this similar to how last season started, albeit almost a month earlier, given we continue to get snow in November and assuming that December and January are a bit drier.

Nice observation! Almost everything has been close to three weeks early this year IMO.