Thread: 2008-2009 Colorado Snowpack Observations

You're likely not off the reservation, its probably me. I agree that surface hoar is going to be a hudge problem in the upcoming days with WFO Boulder saying that we could experience some of the coldest temps in FORTY YEARs.

I always thought that large temperature gradients in the snowpack added facet growth, but I could be way off base...

Woolbury commented to me that in Floral Park the other day he dug a pit to the ground and saw TWO feet of facets at the bottom of the pack.

i hesitate to comment here because i really have very little experience in comparison to the other posters here, but it seems like the reservation is somewhere in between both sides and on both sides at the same time.

We've got a super variable snowpack and snowdepth with our crazy wind event from not so long ago. We've got deep and we've got shallow.

It would seem to stand that the deep pockets already have the 2ft'ish depth hoar fromo the ground from early season snow that was left around when that one cold snap came through a couple weeks ago. I also wouldnt think DH development would change that much in these deeper pockets as whats done is done and the deeper pack helps to insulate against this new colder weather. I havent gotten out there and measured snow pack temperature profiles, so I really dont know. Maybe we'll get some hoar and facet development in the middle layers of the pack?

On the thinner spots on the western half of the compass, id think that we might see a similar scenario to what happend to the deep pockets just a couple weeks ago. Possibilities of full depth hoar.


in a nutshell, super variable sketchy colorado snow pack.
beware and dig.

Good thoughts, Phil. I agree with your sentiments.

Variability has been bothering me since the begining of the season.

1 deep pit from yesterday for what little it is worth as a single data point...

below treeline, just below 11K NE facing, very open trees ~30deg, ~2mi N of two elk pass

250-220 F
220-165 4F
165-135 1F
135-95 P
95-40 P-K-P
40-0 1F-P (medium sized facets with some cohesion)

2xSCT H5 Q2 @ 135

summit, which box of cereal do I need to buy to have the right decoder ring to understand that

Originally Posted by Rontele

Good thoughts, Phil. I agree with your sentiments.

Variability has been bothering me since the begining of the season.

I can probably get behind what both of you are saying, I have only been travelling to and skiing things that are out and out deep lately.

A little more analysis from the previous fatality. Some scary quotes in there.

The three men — a skier and two snowboarders — carried beacons, shovels and probes. Two of them had taken avalanche safety classes, Toepfer said.

“They knew the avalanche rating,” said Don Dressler of the Forest Service. “They had the equipment. They followed the one-at-a-time rules.”

The men did tests — so-called “ski cuts” and “stomp” tests — at the top of the chute to assess its safety, Toepfer said.

In fact, one of those tests triggered a smaller avalanche, about 1 foot deep, that exposed the slope to a substantial amount of weight, Toepfer said.

“Far more weight than you, me, my son, my dog going down the slope at the same time,” Toepfer said.

That was a factor in their decision to ski the chute, Toepfer said.

The men didn’t dig a snow pit to do compaction tests, Toepfer said. The top of the slope was exposed and the men would have been in danger, he said.

Brigham was the last of the three to ride the chute. He was two turns into the chute when it slid.

The avalanche slid on a very small, weak layer about 7 feet deep in the snowpack, Toepfer said. The weak layer was just 1 millimeter thick, he said.

“This layer, if you were out there studying (the snowpack), you’d probably never find it,” Toepfer said.

hudge surface hoar feathers at Ptarmigan Pass today

Here's a pit that we dug a few miles from the summit of Buffalo pass on the western side on a WNW aspect on about a 27 degree pitch. This was on Sunday. The forecast for the Steamboat area was considerable however the pit showed good stability. I also found the area to be much more consistent then summit/vail where there had been massive wind loading.

Here's what my buddy wrote the CAIC regarding information observed from the pit.

--
After studying your reports we decided that our best bet was to head to the boat and investigate this new 3-4 ft. It was truly epic. I have attached a picture of our pit and the failures I observed. I would say most of what you posted was pretty accurate. We dug about 10-11 feet deep to reach the bottom. The poke test didn’t give too many clues but it was apparent that as you moved deeper the snow was much more consolidated than the really light snow on top. About 4 feet into the pack was an apparent hard icey layer that had pine needles in it (this layer did not fail during the testing). About 5 inches above this icey layer and 4 inches about that did fail at level 6. Of note was that the hoar layer in this spot was not as bad as I was expecting. It was about 3 inches in depth and seemed to most resemble this crystal formation: http://www.lpsi.barc.usda.gov/emusnow/comparison/10.jpg a longer hexagonal crystal.
--

Originally Posted by MakersTeleMark

A little more analysis from the previous fatality. Some scary quotes in there.

Which one was this makers?

-L

EV#1. http://avalanche.state.co.us/Acciden...n/20080104.htm

story about Matt Gustafson, who died at EV on Saturday, in the Vail Daily

http://www.vaildaily.com/article/20080115/NEWS/96196623


Matthew Gustafson, who died Saturday in an avalanche in an East Vail chute, stands at the top of a backcountry run three years ago in the same area.




Matthew Gustafson sails off a cornice in East Vail. Gustafson, 33, of Vail, died Saturday in an avalanche in the same area.

A memorial service for Matthew Gustafson will be held at Vail Interfaith Chapel, 19 Vail Rd., Thursday at 3 p.m. A reception will follow at Garfinkels.

Originally Posted by telemike

hudge surface hoar feathers at Ptarmigan Pass today

Tuesday encountered medium and smaller surface hoar ~12 miles WNW of that location... found on most aspects near and below... however I noted that by the end of the day, most aspects below treeline had experienced heating that destroyed or greatly shrank the surface hoar. Unfortunately, sun exposed aspects had developed a very thin sun crust by sunset.

Went out today for the first time in a while. Thought I would share this:

The circled tree is about 50-75 years old. It's roughly 250 feet away from and 75 feet above the Slate River. And at some point during the massive early January storm, the "Climax chutes", as they are known, ripped out and took the tree with it. It's not a great photo, but you get the idea. I guess that's what happens when 4 or 5 feet fall in 3 days.

thanks guys.

this discusion has been extremly helpfull to me.

I too, will start posting my observations, in a latter less wasted state. but as a longtimme lurker...I thank you.\

holla at your boy when you see him eatin a hot dog in DA STREET.

CAIC has a good read on a close call in December in the East Vail area

made a few turns today at vail pass

Poking around in the snow all day didnt reveal a whole lot to be honest.
The top 2 layers, one being the new snow and the other the snow before that felt the softest when punching through until you hit consolidated snow all the way i can reach with my pole without bending over. Felt confident in the snow but the forecast i had just heard and the history so far this season still didnt set well.

so we decided to dig a hasty pit to isolate a few columns just to see whats happened with all this new snow

~11,700 ft - near but below treeline
SW Facing slope / 25*

looking at the pit wall and looking for weak layers it just wasnt obvious that there were any. The whole thing , besides the new snow, was 1-4 finger. I was generally shocked to see such well consolidated snow without any prominent weak layers.

Our compression tests revealed 2 weak layers at ~25 and 30cm (if im remembering correctly) The weak layers, which were extremely thin, were sitting between 2 cohesive slabs with Q1 shears. Really not very confidence inspiring given that they failed simultaneously around 8 wrist taps. Id say the only way to really have found these weak layers on examination of the wall was with a credit card or something similar. Doing some quick hand pits on the way up would have definitely revealed them as well.

We didnt dig deeper than about 4 ft which was all consolidated. Surprised not to see facets even if we only dug 4ft.

overall, not at all confidence inspiring on the snowpack.


on a sidenote
was that you telemike that I was talking to?
i had the white helmet, red jacket, goatee, and 183bros. (had my gf and my buddy with me)
figured youd have said something being i had those skis.

yep - that were me - should have asked about the Bro's

Your assessment is about what I've been seeing too. There are facets down on the ground - a whole bunch of them. I've not been having glaringly spooky test results, but it seems like every day or two we see something new slide in some random place or other.

I too, have very little confidence in the snowpack, and am making conservative terrain choices.

I was out Corral Creek to Uneva Pass today. Very good turns.

oh, yeah....almost forgot.....

AVALANCHE WATCH
COLORADO AVALANCHE INFORMATION CENTER
RELAYED BY NATIONAL WEATHER SERVICE DENVER/BOULDER CO
807 AM MST SUN JAN 27 2008

THE FOLLOWING MESSAGE IS TRANSMITTED AT THE REQUEST OF THE
COLORADO AVALANCHE INFORMATION CENTER.

...AVALANCHE WATCH BULLETIN FOR THE SAN JUANS...GRAND MESA...WEST
ELK...ELK...AND SAWATCH MOUNTAINS OF SOUTHERN AND CENTRAL COLORADO...

THE COLORADO AVALANCHE INFORMATION CENTER HAS ISSUED AN AVALANCHE
WATCH FOR THE MOUNTAINS OF SOUTHERN AND CENTRAL COLORADO.

HEAVY SNOW AND STRONG WINDS ARE FORECAST TO BEGIN SUNDAY AFTERNOON.
FORECAST SNOWFALL IS EXPECTED TO EXCEED TWO FEET BY TUESDAY MORNING.
NEW SNOW AND STRONG SOUTHWEST WINDS WILL RAPIDLY LOAD SLOPES OVER
THE NEXT 24 HOURS.

A WATCH MEANS THAT NATURAL AVALANCHES AND HUMAN TRIGGERED AVALANCHES
COULD BECOME LIKELY.

BACKCOUNTRY TRAVELERS SHOULD USE EXTRA CAUTION DURING THE NEXT 24
HOURS IN THESE REGIONS. TRAVEL IN OR BELOW AVALANCHE TERRAIN IS NOT
RECOMMENDED IN THESE AREAS. SAFE BACK COUNTRY TRAVEL WILL REQUIRE
ADVANCED AVALANCHE SKILLS.

THIS WATCH IS VALID THROUGH 8 AM MONDAY MORNING.

THIS STATEMENT IS OF PARTICULAR INTEREST TO PERSONS USING THE
BACKCOUNTRY OUTSIDE DEVELOPED SKI AREA BOUNDARIES. WHEN NECESSARY
SKI AREAS USE AVALANCHE CONTROL METHODS WITHIN THEIR BOUNDARIES.

FOR ADDITIONAL AVALANCHE INFORMATION...CALL...970-482-0457 IN FORT
COLLINS...719-520-0020 IN COLORADO SPRINGS...970-668-0600 IN SUMMIT
COUNTY...719-395-4994 IN BUENA VISTA...970-247-8187 IN
DURANGO...970-920-1664 IN ASPEN...303-275-5360 IN DENVER. OR VISIT
OUR WEB PAGE AT AVALANCHE.STATE.CO.US

LOGAN
COLORADO AVALANCHE INFORMATION CENTER
2007-08 WATCH 8

Sat. I had some slide activity in the hourglass at BP. On my way down to the entrance I kicked off a 5-10' pocket 4-6 inches deep and nothing else moved so I proceded to the entrance where I got a view of all the hazards (from the top as I had already scoped it from below). decided I was comfortable and dropped in, about 3 turns in it ripped with me in the middle of it all. Luckily only the fresh soft wind slab pulled out 6" deep 15-30' wide.
I str8 lined for the choke as soon as I saw everything get blocky and funneled in with all the snow just trying to stay on my feet and get through the chock with out any hang ups. Got through and out of the way as fast as I could and I was in the clear. At the choke the snow was like white water as it constricted the flow and things seemingly slowed down a bit. At that point the moving snow around me was mid thigh to waist deep, and as I was spit out the other side the snow went a diffrent way than I did.


The aspect was mostly N NE facing and below tree line, pretty steep too(im guessing 40+ish?).

Today we went to tea cup bowl and on the first run we had a soft slab pull out. It was of no suprise as there has been alot of activity on SE facing aspects, there was even signs of natural released small soft wind slab just to the side of the aspect we were planning to be on. Knowing the danger we discussed what might happen if it does rip. We were clear about staying away from "strainers and cheese graters" and having a clean run out just in case. Just as expected it slid and just as planned my buddy had a clean run out. Once the slide stopped we spoke as I could not see him but apparently he was not buried much. His legs were burried about 2 feet deep or less and his pack seemed to give his torso floatation. he came to a stop near the front of the toe.
He was free and moving 3 minutes or less after it stopped.
He had an avy lung and beacon so if he was fully burried the chances of survival were still pretty acceptable to us as I was in my snow shoes not too far away with my shovel and probe out and ready.
The slab ripped 6"-1' on avarage at the crown is our estimate, and I would guess it propogated around 100' wide and had a track of about 100-250'. It was the fresh soft windslab that pulled out and I don't think it stepped down. It also did not run out into the flats but stoped on the lower angle hill above it.

Originally Posted by Rontele

I always thought that large temperature gradients in the snowpack added facet growth, but I could be way off base...

Yep. Stronger gradients = weaker snowpack.
The colder it is outside and the shallower the snowpack is, the stronger the temperature gradient is from 0C at the base down to -whatever at the surface.

Originally Posted by pechelman

Poking around in the snow all day didnt reveal a whole lot to be honest.
Felt confident in the snow but the forecast i had just heard and the history so far this season still didnt set well.

looking at the pit wall and looking for weak layers it just wasnt obvious that there were any.

Our compression tests revealed 2 weak layers at ~25 and 30cm (if im remembering correctly) The weak layers, which were extremely thin, were sitting between 2 cohesive slabs with Q1 shears.

Originally Posted by From Todays Vail\Summit CAIC Forecast

Another slide on Saturday in the K-chute, west aspect, facing Copper Mountain, illustrates the continued deep slab concerns. A party of two found no collapsing and well adhered layers. They commented that the "snow looked good." The first skier dropped into the windblown entrance and then broke two small slabs close to trees that sluffed out quickly. As the second skier entered the chute, the entire top of the chute collapsed and ran about ¾ of the path down to the ground. Fortunately, the skier was able to escape the slide by traversing out the side.

so granted its slightly different aspect and slope angle but I just thought Id point out the similarities to the observations we made and the ones that Party made in K-chute. Just another warning that it might not be so easy to asses stability with the typical surface evaluations especially after this new snow.

be careful in your terrain choices
K would scare the shit out of me right now.

Monarch Pass 1/26/08, @ ~11,600' on SE facing slope of ~33deg.
Mostly sunny, w/ temps ~ mid 20s F.

6' deep pit: Shovel tests on the snow column yielded no failures on all wrist taps(A1-A5) and elbow blows(B1-B10), but settlement of the top 8"(loose powder of less than fist hardness) was observed. A very slight collapse(Q1) was observed on the first shoulder strike(C1) on a layer approx. 18" down. Snow column withstood subsequent shoulder strikes (C2-C10) without shear failure. Column failed(Q3) on final shovel pry on this weaker layer 18" down. This weaker layer was most likely, buried surface hoar, less than 1/8" thick. The bottom 18" - 70" of the column remained intact even when pryed out with a shovel. The snowpack from 18"-70" down consisted of pencil to one finger hardness snow.

It's very possible that a steeper slope (38+ deg) could have yielded different results with a shear failure (Q3) on the weaker layer.

IN the vacinity of Rollins Pass closer to Eldora on Sunday 1/27.
SE facing slope. Pit was ~ 4.5' to the ground...fairly wind affected.
Complete column Q3 failure at C2. (no pic) The entire column sheared off the ~1.5' deep base facet layer. (not really surprising)
The pics show multiple Q1/2 shears at B1-B10 on a different column I made to play around with and take a closer look.

You can see the faceted "ball bearing" texture in the second pic after I liftet the first major top slab off the column.

Berthoud Pass

NW, NE, and North aspects. Blowing pretty hard creating a new windslab layer on top of the existing very hard wind slab. This shallow layer was quite reactive and sluffed on steepish slopes. The wind slab is sitting on top of a very deep layer of junk. Its hard to get things to go, but when they do, they'll go big.

Just can't let this whole thread slide by the season without a shot and a tale with the dreaded deadly ALL black avy icon... the one we almost never see... and in the South San Juans of all places.

-------------
From CAIC 2/4/8

Originally Posted by CAIC

* * * And the snow continues * * *
Observers noted steady snow falling an inch to two inches an hour through the day on Sunday and into Sunday night. Southerly winds strong enough to move snow have been rapidly redistributing ample low density snow. More snow is again in the forecast, though winds should finally ease in strength. All mountain roads across the San Juan are closed at this time. Avalanches have run across all the passes, some quite large. This whole mess will take some time to clean-up. All the recent wind and snow adds up to rapid loading of the snowpack on all aspects and elevations, thus we have issued an Avalanche Warning for the Southern San Juan Zone. Highways 550 and 160 over Molas, Coal Bank and Wolf Creek Passes have been closed due to dangerous avalanche conditions as of this writing. Lizard Head Pass is closed as well.

The danger in the Wolf Creek Pass area is at Extreme.

Unstable slabs are certain on a variety of aspects and slope angles. Access into the backcountry will be difficult at best, especially since most all roads are closed. We recommend avoiding the backcountry at this time. Slides could reach historical size and distance.

--------------
The CB area sounds like some exciting stuff too.

Originally Posted by CAIC

With plenty of new snow (Around 17 inches last 24 hours with over 2 inches of water) and moderate to strong ridge top winds, we are expecting another natural avalanche cycle. Our main avalanche concern remains in the upper snowpack, where new snow may overload weaker layers. Several weak layers exist including buried facets and low density snow that fell earlier in the week. New snow may slide on hard slabs from our last major wind storm as well. Look for increasing danger as the snow piles up. While most avalanches will release in upper layers, the chance of deep slides still exists. An avalanche initiated higher in the snowpack has the potential to step down into the weaker snow underneath. Areas that slid earlier in the season are likely to slide again.

The avalanche danger will continue to rise to HIGH overall as snow accumulates. Access into the backcountry will be difficult, we could see some long running avalanches, and possibly activity in areas not normally suspected for slides. Avoid traveling on or below steep slopes at this time.

Interesting note: Over 205 inches of snow has fallen near the Crested Butte Ski Area this year. That is more than the entire 2006/07 year and it is only the beginning of February!