Mores Creek Summit Backcountry Skiing

Pilot Peak January 23 2012

2012-01-25T06:32:00.001-07:00

The skiing at Pilot Peak last Sunday and Monday was described as exceptional by Jim and Erin (Blog contributors). Well, it was no different Tuesday January 23rd. The cold temps and clear nights have kept the surface snow in primo conditions! The New Pow depth was 35 cm.

Below a video of the skiing at Top of The World and Almost Top of the World. Keep an eye for avalanches track at the sides of the ski runs.

The day started as a blue bird day, no wind, cold, ... just perfect. The next two pictures correspond to very first meadow encountered when skinning up from the first pull-out after Mores Creek Summit snowmobile parking area. Notice the outline of the slab (partially covered by new snow) that avalanched last Saturday (Jan 21st).

The slope angle for this slope measured 31 degrees! A picture looking down, above the fracture line is shown below.

This last avalanche cycle affected many slopes where I would have either expected avalanches to occur higher in the slope, or slopes with 30-34 degrees to be anchored by the heavy brush of Mores Creek Area. Predictably, slopes steeper than 35 degrees avalanched, but MANY slopes in the 30-33 degree range also slided, and crown fractures were sometime found midslope, just as the slope from the pictures above.

The most impressive slide was at Top of The World (or Round the World). This avalanche ran 1300 feet in vertical. In fact the debris field filled and covered all of the gullies at the very bottom of this run and stopped below the elevation at the bottom of "Almost Top of The World" ski run.

I skied to the bottom of the avalanche debris field in complete disbelief ... it ran beyond the alpha angle of 18 degrees, and the extent and size of the debris toe has completely filled the complex gullies. There were trees and brush that were uprooted and have make this ski run longer!

I am going to be conservative and classify this avi as a D3.5R5 - but if you stand at the bottom of the debris field it was obvios that a rail car would have been destroyed (D4). But D4 are NOT suppose to happen at Mores Creek Summit! This most be a 1:20 year event. This winter is my 20 year skiing this area, and I have never seen anything like this at Mores Creek Summit.

100 feet above the toe of the avalanche debris, looking up to Top of the World"

1/3 of the way up, looking down into the avalanche path, this one of the gullies that channeled most of the avalanched snow.

2/3 of the way up, looking down into the avalanche path

View of the full track down slope from the crown.

We skied two runs at both flanks of the Top of the World Avalanche. The starting zone average angle was 31 degrees, with a steep sections measuring 33 degrees. There is a steeper line with a rollover at 34 degrees above the fracture crown that was not pulled by the avalanche. I typically do my snowpit above this rollover, and was surprised that this avalanche broke lower in the slope than I expected.

South East Flank of the Avalanche.

North East Flank of the avalanche.

Crown of the Avalanche

Full view of the Avi from mid track

Side view of crown

Crown wall made smaller by new 35 cm of snow. Mark standing inside the avi.

There many other significant avalanches from Saturday cycle at the Knob, Almost Top the World (4 avalanches in that area alone), The Lower glades (2 avis), and the eastern flank from the baldy spot we descend to ski the Knob Ridge. This last avalanche was D2.5-3! Just CRAZY!

The new snow at Sunny aspects (NEE, E, SE, ...) had a delicate layer of surface hoar (SH). Please keep an eye on it in case is not destroyed by the new snow predicted by Wednesday. Although, as we skied out yesterday, there was a deposition of 1-2 cm of new snow that most likely already covered this delicate layer of SH. Furthermore, below the snow surface, there is a low density (very skiable) layer of Near Surface Facets called Diurnal recrystallized snow formed by the relatively mild days and cold nights.

I would not trust the avalanche paths once they get a new slab formed. The bed surface was a pencil hard and capped by a slippery and delicate layer of facets.

Thus, for the next storm cycle it is important to track the SH and NSF at the aspects that get some sun. The deep north should be approached with deep suspicion due to the deep instability (buried depth hoar - DH).

Also - and hate to do this - keep an eye on the rain crust layer buried 35 cm down. Between 7000-8000 feet, this layer has formed a well develop layer of large facets. This layer is easy to detect. Testing of it produced CTMQ3 results. A temperature gradient it is still present, thus it might go from a Q3 to Q2. Performing a loaded column test (simulates a storm by loading column with a block of snow) did not changed compression test (CT) test results. Extended Column test did not showed propagation propensity for this layer either.

Report for Pilot - Jan 22, 2012

2012-01-22T21:19:00.001-07:00

Excellent report from a Jim, a long time BC skier:

During our tour today we saw many class 2 and 3 avalanches that occurred prior to Saturday afternoon. Crowns were 3-5 feet deep and bed surface was the late December rain crust. Most slope angles were 35-38 degrees, but one was 31 degrees. Many of the avalanches occurred in the same place where the late December avalanche cycle scoured to the ground, but some occurred where it did not.

This avalanche cycle is thought to be unprecedented in the opinion of our touring party who has skied extensively around Mores Creek Summit for up to 15 years.

Class 3 on mid- to upper-30 degree SE aspect in Round the World Bowl:

Class 2 on 31 degree E aspect:

We stayed on slopes below 30 degrees and found excellent conditions with supportable snow covered by 6 inches of fluff.

Trail-breaking was easy and skiing was fast. Below ~6800 feet a rain crust was present below the fluff.

We were shocked to see a skin track and ski tracks on the Freeman "Exit Chutes". We questioned that decision-making given (1) numerous class 2 to 2.5 avalanches on similar slopes located a few hundred meters N of the tracks, (2) High avalanche danger posted for ranges surrounding the Boise Mtns. and (3) the plethora of low-angle slope options in the Mores Creek Summit area.

Chago comment:

Yesterday (Saturday 1/21) I was quite surprised at the sensitivity of the snowpack. Agree that this level avalanche instability is unprecedented for Mores Creek Summit. I hope you do not mind posting your comments, since they will contribute to create awareness.

In addition, a week ago I was surprised at the sensitivity of the snowpack at Banner Summit/Copper, and that was prior to the BIG snow event. I am spending next weekend at Norway-Halfway-Oregon, and it is very likely that I will have to tip-toe around the big stuff over there.

Readers of the this blog, please take a look at this avalanche accident report:

Avalanche Fatality - 2012/01/18 - Colorado - Burnt Mountain Near Snowmass Village

The avalanche that claimed a life on this accident was very small, and typical to the terrain that can be found at Mores Creek Summit:

The avalanche was 14 feet wide, ran 30 vertical feet, and was 2 feet deep at the crown. Please carefully evaluate any slope you are about to ski, and have the presence of mind to anticipate consequences, particularly during this period of deep instability.

Another blog reader posted the following comment I think it is important to integrate into Sunday's report:

I skied Pilots on Sunday as well. Saw a large slide over on Freeman on a NW slope. The north bowl of Pilots had slid as well, with a 4-5ft deep crown-line and looked to be wider than a football field's length. However, heard no whumpfing while skinning up the ridge to Pilot's. We opted to ski low-angle (<28 degrees) south-facing aspects, and had a fun ski day!

We also observed several snowmobilers out and about - some were high-marking up on Freeman's on slopes with similar aspects to the slope we'd seen a slide on. EVERYONE should be careful in the backcountry right now, snowmobilers and skiers alike!

That said, low-angle, south-facing slopes are skiing very well right now with an awesome layer of new snow!
-Erin L.

Mores Creek Summit - Jan 21 2012

2012-01-21T23:35:00.000-07:00

Today I drove to Mores Creek Summit to assess the impact of the significant precipitation event, as well as making turns in a set of new skis that have been patiently waiting for the right conditions.

My new POW tool!

As we all know the precipitation that commenced Wednesday and winded down today brought the snow levels to average conditions:

The Snotel at Mores Creek Summit reported a whopping 75 inches, an increase in excess of 48 inches (4 feet!). It was no surprise that some pull-outs were not plowed (such as Winter's Corner), and that the parking area at the Summit was limited in parking space. With very few options available I decided to make few laps at Freeman. There was another party at Freeman that selected to put an uphill trail on the main ridge. I still was not sure there was not going to be combat with the brush approaching from the ridge, and opted to built a second uphill track close to a run some call "Elevator" (ski line dropping to the switchback). As expected, trail breaking required more work due to the unconsolidated nature of the new snow.

No whumpfing, cracking, or other sign of instability were present during the climb and approach via a NE subtle ridge to the 7000 feet level. During the drive, and ski touring, crown fractures were visible at SW, W, NE, NW, and N aspects. The fractures appeared to be 25-30 cm deep that ran during the storm cycle only at very steep 37-39 degrees slopes between 6000-7000 feet. Terrain above 7000 was obscured and/or not visible. NO avalanches were observed that might have run on the old snow interface.

Some brush still poking out even with 4 feet of new snow!

Mores Creek Summit Winterland

I was very fortunate that the camera worked early in the day, and allow me to record the PST (Propagation Saw Test) and Ct (Compression Test). After finishing the the snowpit, my Nikon point & shoot refused to work - it reported a "lens error". Too bad, since it did not allow me to document the several areas with crown fractures.

Below a video for the PST test in a 26 degree slope with East aspect. As you will notice in the video, I was surprised by the propagation at the interface between the New snow and old facet layer (~65 cm from the ground) after just sliding the saw )blunt side) less that 5 cm. The slab experienced a sudden collapse after the propagation, suggesting a Q1 score.

The next video is for the compression column test. A previous test, not recorded resulted in a CTVQ1, or column failure during isolation. On this video, a second column was isolated and failed after just placing the shovel blade in top of the column, perhaps between a CTV and CT1Q1.

This was a surprise to me, to find the deeply buried facet layer so sensitive at relatively low elevation (6800 feet) and after being buried so deeply (1.3 meters) by a slab.

Snowpit: New snow from 65 to 195 cm

Between 65 and 155 cm the snow was 4 finger hard, and fist hard from 155 to the surface at 195 cm. A very thin and delicate rain crust was present 20 cm below the snow surface.

The weak layer - a fist hard 2 cm layer of large facets - was found above the pencil hard ground to 63 cm old snow layer.

The snow pit work did not detected any remarkable or reactive layer in the new snow (top 1.3 meter). While skiing down in terrain 30-32 degrees, no new snow surface instabilities were detected, and ski cutting in wind loaded and steep roll-overs did not produce results.

Considering that evidence of "deep" instability was found:

high probability for trigger likelihood (Easy CT scores)
high probability for fracture propagation (PST 5/100 End)
high likelihood of slip after fracture nucleation and propagation at a depth of 1.3 meter (Q1 Scores)

It would be prudent to approach steep slopes ( greeter than 35 degrees) at Mores Creek Summit Area with a high level of prudence. And slopes that have avalanched this season should be considered suspect-ful (Freeman-42, Almost Top of the World, Head waters of Edna Creek, ...).

Last weekend a second Avalanche L1 course was completed by the 705 BSP. We had a good time at Freeman on Saturday, and a fabulous day at Banner Summit on Sunday.

Students at Freeman (Top) and Avi Instructors demonstrating companion rescue.

At Banner Summit, there was about 25-30 cm sweet POW snow (not facets!) that was skiing incredibly well in top of the old facets.

Carl 3X - enjoying the turns last Sunday!

Results for trigger likelihood (CT), and slip likelihood (Q) were moderate CTMQ2 at the students snowpits. However, the propagation likelihood was high (ECTP, PST 40/100 END). Recent avalanches were spotted in the vicinity, thus we restricted skiing to slopes below 35 degrees.

Carl and Judy gathering data.

Pedro with a couple of students at Banner Summit

Thus, it appears that the reactivity of the winter drought facet layer along with its ability to propagate fractures failures will stay with us for while. :(

I would like to take a few lines to congratulate the students that completed the AVI L1 course last MLK weekend. And knowing that they enjoy this blog, I will include few pictures below for their enjoyment. Thanks Judy for the PICS!

Playful Skiing at Freeman Peak - January 4 2012

2012-01-05T07:14:00.003-07:00

We might not have an abundance of snow in South Western Idaho, but once you get above the 6500 feet, the snowpack has been generous, and there are some great turns to be made. Check the video link included below:

Not only the skiing and the snow quality was great, but I spent the day with Pedro (my son), John T. college kids, and the always funny Mike L.

Ski partner approaching Freeman Summit, with great views of the Boise Mountains to the East.

There were no signs that Freeman has been skied after last week storm cycle. And we had the full hill for us today. The best skiing was between 6500 and 7500 feet at protected slopes.

Ramp above 7000 feet leading to Freeman Summit.

A thick layer of "diurnal re-crystalized" crystals (or Near Surface facet-NSF) between 6500-7500 feet in elevation suggest that the warm temps experienced lately have not resulted in a crust or melt/freeze metamorphosis at this elevation range.

The snow above 7500 feet, even at protected north aspects showed signs of densification or the formation of a crust at NE and East aspects. We observed air temps up to 4-5 degrees C by mid-day. This is very likely the result of the "inversion" due to the mild and tranquil weather, thus somewhat cooler temps at mid-elevations is making skiing fun and forming very skiable NSF crystals, but warmer temps at higher elevations is making the skiing experience "instruktional" with its variety of crusts - Bummer!

Below the snotel temp data for Mores Creek Summit (6100 feet) for the last seven days documents very well the balmy temps (above 0 deg C) since January 2nd. Similar temperature trends can be observed at most snotel stations. In fact, reports froms a Boise friend that skied Copper Mountain last Tuesday confirmed that the warm weather negatively affected skiing there.

Below few pictures we snapped today of the last avalanche cycle at Freeman:

Slab fractures - one of the several observed.

More fractures.

And more fractures, and missing slabs that avalanched.

Crown fracture (top left) with debris (center).

Some of us are very fond of the steep but short chutes 600 feet below Freeman Summit. It is important to remember that these chutes are called by some us 42's for a reason, they measure 42 degrees in steepness. Below a series of pictures of one of the chutes:

Crown of avalanche at 42.

Track and flanks of avi at 42.

Debris field and toe of the avalanche at 42.

Deep debris field due to a very dangerous "Terrain Trap". The trees at the Left side of picture are taller than a person.

Stability test results at East Aspects at 7400 feet resulted in ECTX and CTN results. Last Saturday, the buried depth hoar and facet layers were moist. During the last four days, the buried layers have gained strength as the snowpack has refrozen.

Stability test results at the crown of the Avalanche at 42's slope resulted in CTN scores. It was quite interesting to observe at the crown fracture, the presence of a distinctive layer of what was free water frozen (this is a deep north slope) and with an appearance of water flowing between the slab and weak layer.

Three meters away from the flanks of the avalanched slope at 42s, another nearby slope produced stability results with CTVQ2-50 cm down (DH) and CTMQ1- 50 cm down (DH) scores. This was very concerning, since a CTV represent a spontaneous block failure during its isolation. In other words, considering that 42s aspect has a North aspect, we need to continue to be suspicious of slopes steeper than 32 degrees at protected slopes and with North aspect component.

Pilot Peak - Very Nice Skiing the last day of 2011

2012-01-01T08:38:00.001-07:00

The last day of the 2011 year had a conflicted snowpack, with two very distinctive personalities; Fantastic Skiing above 7000 feet and a very unstable snowpack. It felt like dealing with Batman's Two-Face character.

The skiing above 7000 feet was sweet. East aspects unaffected by wind had 20 cm very low density snow that have experienced some level of "near surface facetting" due to warm snowpack underneath and cold temperatures during the evening.

Nice Pow at 7800 feet - Pilot Peak, Lamar Ridge Area.

The snotel for Mores Creek summit seems to be taking some time-off for the holidays (no data available for 12/31/2011), but the Trinity Mountain snotel at 7770 feet, is a good representation of the temps and precipitation experienced by Boise Mountains snowpack above 7000 feet.

Trinity Mountain Snotel

Notice in the above chart the cross over of "dipping temps" (red line), and NEW snow (other red line) between Dec 30th and 31st. The overnight and early morning low temps at -10 Deg-C assisted in further making the snow surface "non-cohesive", and as I stated earlier, very skiable! Below a short clip of low angle skiing in a a ridge line.

But the snowpack had also a much dark face. A very sensitive weak layer was buried under a very cohesive slab with a thickness 50-60 cm. Below a picture of a series natural releases at Pilot Peak on a very popular slope some call "Almost Top of the World".

Very large whumpfs were present pretty much everywhere though-out the whole day, and collapses of snowpack in the range of 2-4 cm were not rare either.

Stability tests were not surprising considering the observation of natural avalanches and significant wumpfing and collapses. Multiple "Extended Column Tests" (ECT) triggered a propagation with fewer three hand taps, and released with Q1 quality (rapid and clean release, along with sudden collapse). Compression Test (CT) also failed "Easy" with Q1 scores.

A test pit at an East aspect, 7700 feet, 24-26 degree steep showed the following results:

ECTP3Q1 55 cm (facets - 2mm)
ECTP8Q1 55 cm (facets - 2mm)
CT3Q1 (SC) 55 cm (facets - 2mm)

Trigger and propagation likelihood scores are insensitive to angle, but we were surprised with the energetic Q1 scores at the low angles we tested (24-26 degrees). Slip Likelihood (Q1 scores) are a measure of the slip or slide likelihood once a fracture failure has been triggered and propagated in the snowpack. This reflect the ease of releasing avalanches in relatively lower angles. We limited our skiing during December 31st to slopes shallower than 30 degrees!

The snowpack structure we found is summarized next:

HST (snowpack depth) = 110 cm.
20 cm of "Non-Cohesive" (very skiable snow) with FIST hardness.
35 cm of dense slab progressing in hardness from 4-FINGER to Pencil at the weak layer interface. Snow crystals were round and small (less than 1 mm).
55 cm of heavily faceted grains (2 mm) with FIST hardness. This layer was very moist! Free water can be easily detected and squeezed from the snow.

With the above snowpack structure it is not hard to identify a WEAK snowpack structure with many elements present in most avalanches:

Slab is present! Difference of hardness larger than 1 step (Pencil to Fist).
Persistent Grain Types are present = FACETS!
Difference in snow grains larger than 1 mm between slab and weak layer.
Weak layer is within the top meter of snow (55cm).

Thus what are commonly called "lemons", four lemons were detected. The other lemon, relates to thin weak layers (less than 10 cm), but there is a very thick layer of facetted grains. The high reactivity and Q1 scores of the snowpack is most likely the result of a very cohesive slab, but in particular a thick (5+ cm) and pencil hard rain crust right above the weak layer.

As aside note, yesterday, the conditions reminded me a lot about the well documented instabilities caused by capillary barriers, were free water flows within the snowpack until it finds a structure that acts as sponge absorbing water responsible for "wet slab avalanches".

Rain events during December 28th and December 30th heavily soaked the facetted and now buried weak layer with rain. The snotel chart for Mores Creek Summit included below shows the extent rain in the snowpack Notice the precip line (red) augmenting but not the snowdepth line (blue).

It is reasonable to expect that the water soaked basal facet layers will assit in the stabilization of the weak basal structure by promoting rounding, and above all once the free water freezes deeper in the snowpack.

Stability test results for Friday december 30th by another observer on a North aspect slope at 6200 vertical feet were:

CT3Q2
ECTP7Q2

We did NOT observe any natural activity anywhere below 7000 feet. The test results for Friday suggest that evidence of instability was present (High likelihood of propagation and triggering), but Friday's rain soaked snowpack at 6200 feet lacked the elements necessary to make it slide after a failure.

Back to the topic of ski conditions, the lower 500 feet of the mountain require some careful navigation to avoid brush. However the top 1000-1500 feet are skiing incredibly well. Check the next video:

Post Christmas Present - Wx Change = SNOW!

2011-12-24T20:26:00.000-07:00

Late Christmas Present is coming!

A major weather pattern change will shift the jet stream further south bringing a good chance of rain and snow to the region between Christmas and New Years Day. Expect accumulating snow in the mountains and rain in the valleys beginning on December 27th.

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE BOISE ID
548 AM MST MON DEC 26 2011

IDZ011-013-028-033-ORZ062-271300-
WEST CENTRAL MOUNTAINS-BOISE MOUNTAINS-CAMAS PRAIRIE-
UPPER WEISER RIVER-BAKER COUNTY-
548 AM MST MON DEC 26 2011 /448 AM PST MON DEC 26 2011/

THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF SOUTHWEST
IDAHO...WEST CENTRAL IDAHO AND NORTHEAST OREGON.

.DAY ONE...TODAY AND TONIGHT

NO HAZARDOUS WEATHER IS EXPECTED AT THIS TIME.

.DAYS TWO THROUGH SEVEN...TUESDAY THROUGH SUNDAY

SIGNIFICANT PRECIPITATION IS EXPECTED OVER THE REGION TUESDAY
NIGHT THROUGH THURSDAY.  HEAVY SNOW IS POSSIBLE ABOVE 5500 FEET.

Snow Probabilities of 4 inches or more for 12.27-28.2011

Be mindful that NEW snow will be falling in top of a very weak snowpack.

Pay attention to wummpfs and collapses. Do not ignore avalanches, even small ones at road cuts on your way to your favorite ski touring destination.

The snowpack in our region is heavily facetted and it will be experiencing changes in temperatures and loading (rain, new snow, wind transported snow, total storm snow deposition). Remember, the new NEW snow will become a slab in top of a weak layer of facets.

Snowpacks becomes reactive when experiencing fast strain rates. And this weather change promises conditions that will strain the snowpack.

We will know by next weekend how much backcountry skiing and ski touring will improve with more snow. Below the outlook for the next weekend, if these prediction holds we should see more snow through next weekend.

6-10 Day Precipitation Outlook
Dec 31 2011- Jan 4 2012

Anthony Lakes Backcountry and AVI L1 course 12/17-18/2011

2011-12-19T07:11:00.000-07:00

Last weekend was a hoot! What it lacked in snow it was more than compensated by great camaraderie.

Due to the low snow conditions at Boise, the 705 Backcountry Ski Patrol first AVI L1course for the 2011-2012 was conducted at Anthony Lakes Ski Resort Backcountry. We are grateful to the Anthony Lakes Mountain Management and its Local Ski Patrol for their enthusiastic support. Also, we will be negligent by not extending our thanks to the North Powder Cafe for allowing us to have AVI instructors morning meeting at 6AM, and for Cheryl that keep renting to us the fabulous accommodations at the Parker Cabin.

Brad leading the field transceiver talk Saturday 8 AM

As usual, the 705 BSP counts with several National Ski Patrol Avalanche Instructors and the instructor to student ratio was kept well below our preferred 1:4 ratio. All instructores are volunteers, and are exposed to the rigorous development program driven by John Taggart, the Eastern Oregon and Southwestern Idaho NSP Avalanche Advisor. In total we had one instructor of record (Chago), two other lead instructors, two assistant instructors. The 705 BSP AVI courses also include an outdoor medicine specialist (OEC and WFR Educator) to make certain that AVI victims medical care is appropriately covered during the course.

Anthony Lakes Lift

After spending the early hour of the morning at the base of the ski resort covering Avalanche and rescue skills we took the lift to the top of the resort, and left the ski boundaries to tour Poster Ridge. We were delighted by the clear skies, sunny, and calm wind ... we could spot Mount Hood as well as Mount Adams ... Great Views.

Absolutely FANTASTIC views!

Some have a lot MORE fun than others!

Going up!

After touring along the south west ridge of Lookout Peak we started the snow pit work with the students.

Kevin - Anthony Lakes Ski Patrol Director is leading a chat with the students after the morning snow-pit work concluded

It was notable to observe the preparedness of some of the students, with their stove at hand and preparing their warm lunch!

Lunch time!

Hard to beat ... time in the outdoors!

At the end of the day we congregated at the local and famous Baker City Barley Brown's brewery. It was perfect, good food and new friends all sharing the highlights of the day.

The next day started with the 8 AM tour planing session.

Anthony Lakes Lodge

Promptly before 9 AM we started the tour over to Angel Basin.

The day started overcast, and by mid-day snow was precipitating. There was a total of 2-3 cms of new snow by the end of Sunday that rested in many places above the surface hoar we observed Saturday.

Surface Hoar

Avi Students working in their snowpits while it started to snow.

The complex and organized rescue exercise scheduled for the afternoon was preceded by warm lunch in front of a fire in top of the snow - an important skill for backcountry ski tourers.

Once back at the ski resort, and as darkness and snow fall closed the day, we meet with the AVI L1 students to wrap the day. We reviewed the outcomes of the course and completed the day with a demonstration of Snow Pulse air bag.

Later in the week I will post a report about the snowpack, weather and avalanche observations for Anthony Lakes during the weekend of December 17th and 18th for those wanting to stay updated on the snowpack development in that area.

As a final note I want to express my deepest gratitude to all of the individuals and organizations that support the 705 BSP with their personal time and spirit of volunteerism so that we continue to provide Avalanche Level 1 courses to the public at no cost. These commitment to make the backcountry safe and accesible to the public is a pay it forward endeavor, and we are certain that the NEW graduates from this AVI L1 course will continue to spread the gospel of safe winter travel and pass forward their new skills.

Cape Horn Ridge - Point 8995 - 12.11.2011

2011-12-12T06:46:00.000-07:00

Gorgeous views from any high point at Banner Summit Sunday December 11 was the rule. Most high peaks from surrounding ranges could be easily identified.

Top of Cape Horn ridge first false summit at 8995.
Copper Mt. in the background to the left.

The skiing off the 8995 feet high point in the Cape Horn "horse-shoe shaped" ridge, just across I21 and North-west of Copper (8965 feet) was phenomenal.

East Facing basin below 8995 point Cape Horn Ridge.

The snow surface at East facing slopes was soft and creamy. It only took telepathy to execute turns on such high quality "hero" snow. And the massive amounts of near-surface facets had a healthy "frosting" of "surface hoar"!

Surface Hoar at East Aspect at 8400 feet.

As we discussed in a previous posting it is always a good practice to plan a tour. The map illustrates the ridge we used for the skin up, and the intended ski lines.

8995 Point - Cape Horn Ridge Topo Map

We decided not to ski the SSW lines denoted by purple lines, and stick with the NE and E aspects. The skiing was "way too good" to gamble with a melt freeze crust at south aspects.

We started the tour by listing the snowpack concerns in our Blue Books (Snow, Avalanche, Weather, Observation Journal):

Windslab in top of facets
Unpredictable thin snowpack with basal facets (depth hoar)
And buried obstacles

At 8700 feet we identified a very hard windslab in a steep north looking slope. This thick slab was sitting in top of facets, and it was spooky with its drum like sound and dark appearance (shaded due to winter low angle of the sun). This slab very likely was the result of the strong North winds a week ago. A snow pit 30 meters away but at a less steep slope (34 Degree) and on a spinal ridge facing East produce a snowpit the following elements:

Surface - 1 cm - Hardness: Fist (F), Surface Hoar (SH) 3-4 cm crystals
1 - 30 cm - Hardness: F, Near Surface Facets (NSF) 2 mm crystals
30 - 50 cm - Hardness: 4 Fingers (4F), Mixed Facets 1 mm crystals
50-52 cm - Hardness: F, Depth Hoar (DH), 2 mm crystals
52cm - Soil, rocks, dirt ...

It is easy to recognize that a slab (hardness of 4F) is sitting in top of a weak layer of DH (hardness of F). Also, that the snowpack is shallow with a depth of 50 cm!

The gradients were in excess of the 1 degree per 10 cm as it can be seen below:

Ts = -3 deg-C
T10 = -6 deg-C
T20 = -6 deg-C
T30 = -4 deg-C
T40 = -2 deg-C
T50 = -1 deg-C

The numbers next to T denote the depth below the surface. Notice that there is a 3 Deg-C per 10 cm gradient at the top of the snowpack surface. That gradient explains the formation of Near Surface Facets. In addition there is a 1 deg-C per 10 cm gradient at the bottom of the snowpack, that is responsible for the formation of basal facets we call depth hoar. It is not hard to realize that during the night, the top of the snowpack will see temperatures below -10 deg-C reverting the gradient in the top of the snowpack. We call this type of Near Surface Facet process Diurnal Re-crystallization.

I felt it was appropriate at this time not to chart the profiles and temps, but to show that charts are not a pre-requisite for understanding the data, and the purpose of this write-up is to assit folks in making sense of the data that can easily be collected in the field.

Stability tests at the East 8700 feet slope with 34 degree slope produced the following results:

ECTN29Q3 at the 50 cm DH layer
CTHQ3 at the 50 cm DH layer (3X - 3 times)
PST 80/100 END

In a previous blog posting we discussed the Stability Quadrants. The above data can be summarized in the following format:

Trigger Likelihood: Low
Propagation Likelihood: Low
Slip/Slide Likelihood: Low
Structural Weaknesses:

Presence of slab: 4F Slab in top of Fist hard DH weak Layer
Weak layer below top 1 meter - 50 cm
Weak layer thickness is thin - 2 cm
Difference in slab and WL grain sizes - 1 mm
Weak layer composed of persistent grain type - DH

Even when the stability tests failed to find "instabilities" and could provide some comfort, the snowpack in our area is thin and very variable. It only takes some old patch of early snow to be buried below the facets to provide the much needed missing component to change test results. Or the formatin of heavy and hard windslabs in steep terrain, such as the one we found. I also still remember last week, when at Angel Basin (Anthony Lakes-Oregon) I found a similar snowpack with PST 40/100 End results, suggesting a high likelihood of propagation potential (propagation when less than 50% of full length is cut). The only difference is that the November snow was deposited above an isolated patch of October snow.

Since the snowpack is thin, it was very easy to check if the structure of the snowpack was changing as we skied. In addition we avoided the deep north steep slopes with windslab!

Sunset Peak 12.10.2011

2011-12-10T17:35:00.001-07:00

This blog is named after Mores Creek Summit for one reason ... and it was about time for me to hang around Idaho City Mountains this winter. This is my season first visit to Mores Creek Summit backcountry, and I was very pleased with the skiing. The coverage is thin, but the re-crystalized snow is not skiing bad at all. Of course, it helps when you own rock skis, and they have been hammered during the last 4 weeks of BC skiing.

Considering the snow depth of 20+ inches reported by the Snotel at Mores Creek Summit, I set my sights on Sunset Peak, and took advantage of the logging road to avoid the lower elevation brush.

Mores Creek Summit Snotel for the last 30 days.

It was a clear, sunny, and relatively warm day (0-2 Deg C). I was surprised no other folks were touring Sunset Peak today, but there were enough old ski and snowmobile tracks suggesting that it has been popular during the last week or so.

Last week while ski touring Copper Mountain-Banner Summit, Angel Basin-NE Oregon Elkhorn Mountains and Brundage Mountain, surface hoar was not present in the areas we toured and skied. That was not the case today at Sunset Peak, there was an ample supply of surface hoar (SH) at W, S, E aspects at elevation above 7000 feet. Most of the snowpack has been transformed into facets, and I am not looking forward to have this SH layer buried in top of another layer of facets that has experience settlement and densification without experiencing significant sintering. In other words, the SH will be sitting in a weak layer capable of becoming a fracture failure surface once we have slab sitting in top of the buried SH.

As mentioned earlier, the snowpack was thin at Sunset: 30 cm at 7000 feet, and 50 cm at 7700 feet. It helps that the snowpack is dense and facetted, otherwise the lack of a base would have been problematic to the ski bases and skiing in general. I should mention, building an uphill track on facets has the added benefit of testing your skills in setting appropriate angles and providing an extra work-out that will pay-off later in the season.

Today was a relatively warm day, with south winds that did not mitigated the significant facetting the snowpack is experiencing;

at 7000 feet; West aspect; Ts = -8 Deg-C, T10 = -6 Deg-C, T20 = -3 Deg-C
at 7700 feet; North Aspect; Ts = -8 Deg-C, T10 = -4 Deg-C, T20 = -3 Deg-C, T30 = -1 Deg-C

For both locations the gradients were much higher than the critical 1 Deg-C per 10 cm. This is the reason that the WHOLE SNOWPACK is turning into facets. In addition, it explains the ECTNQ3 - 40 cm down (DH, facets), when the snowpack lacks a defined slab structure.

Although most of the wind breakable crust lower in the mountain (below 7600 feet) has disappeared due to faceting, there is still some resilient thin breakable crust surfaces at NW, N, NE aspects close to Sunset Peak summit. I can handle buried obstacles, but this summer I skied breakable "cardboard" wind crusts at Las Leñas to last a lifetime, thus I am determine to stay away from any crust this winter!

I will go ahead and publish this posting, but once I get back later tonight from a Christmas Party I will post a video from today's tour and skiing. The views were phenomenal!

Tomorrow, might be a good day to explore some stuff near Copper Mountain. Keep checking the blog!

Brundage 12.6.2011 and Transcievers Selection

2011-12-09T19:53:00.001-07:00

Lick Creek Range from Brundage 12.6.2011

Gary - Brundage 12.6.2011

Chago - Brundage 12.6.2011

Brundage as most of SW Idaho is low in snow, but the skiing is not bad at all. Late in the afternoon I skinned up and skied a single run with friends. Conditions were better than I expected, and with proper selection it was possible to ski untracked lines with 10-15 cm of soft pow in a good base and avoid buried "mines".

One of my companions had a loose binding, he had to ski down on a single ski!
Notice the bright moon.

Earlier this week I had the chance of spending the day with University of Idaho graduate students talking about the Science of Avalanches. During the morning we meet at the MOSS campus in Ponderosa State Park, and we finished the morning simulating flour (slab) and sugar (weak layer) avalanches in an inclined board.

In the afternoon the graduate students had the chance to dig snowpits at Brundage, look at facet crystals, perform stability tests, and practice with transcievers.

The Brundage snowpack at North and West exposures is shallow at 6000 feet, with no more than 50 cm at the deepest location. North aspects have a snowpack that is mostly faceted, and with some layering but very little hardness (or cohesiveness) difference between the layers. West aspects showed a more settle snowpack with round grains in the bottom 30 cm, mostly small facets above the 30 cm depth (from the ground). The top 10 cm (40 to 50 cm surface layer), consisted of mixed grains (facets showing rounding). Stability tests did not find evidence of instability.

Several students were interested in transcievers recommendations. And during the last few weeks many friends and acquaintances continue to ask for guidance in the purchase a transceiver.

The above slide set summarizes the statistical analysis I performed for a transceiver company. The results are very clear, Analysis of Variance did not detected statistical difference in search perfomance between transcievers manufacturers/brands for novices as well as Guides. However, the Ortovox F1 included in the Box & Whisker charts (bottom chart) did not performed well in the rescue scenario, and I removed that transceiver from the ANOVA (top chart).

In summary, this study suggest that any of the 2 and NEW 3 antennae transcievers will result in good search times, and brand selection is a personel preference. Also it documents that novices can improve times with rescue practice in order to reach comparable search times attained by "Guides".

For advanced recreationists, avalanche professionals, and mentors/instructors. I strongly recommend to acquire a 3 antenna transceiver. The motivation is that this user has influence on his peers, and it is important to model behaviors as well as rescue gear we want students and ski companions to own.

The most important characteristic of a 3 antenna transceiver is it ability to greatly suppresses the dual minimum when transcievers are coupled (antennas have same orientation). This is not critical for a well trained professional, but it is important for novices. And the best way to encourage novices to acquire a 3-antenna is not to brag how well a pro can search with old gear, but to be a role model, and own a 3-antennae transceiver.

Trip Planing and Stability Assessment Quadrants - Anthony Lake BC Tour

2011-12-05T19:57:00.001-07:00

"How do you plan a backcountry ski trip? This is an important skill to refine. Trip planning allow you become acquainted with the area you plan to tour, identify the best snow conditions for riding, and anticipate instabilities.

Last Sunday December 4th a group of friends from Boise ventured to visit Anthony Lakes (YES - the resort is OPEN!). My friends have not been to Angel Basin before, and I was stoked to show them the superb ski lines and wonderful POW that can be at a sub range named "Little Alps" in the Elkhorn Mountains of Eastern Oregon.

When planing a tour, first you need to produce a topo map from the area:

Anthony Lakes and Angel Basin Topo Map

Red and blue lines are uphill tracks and yellow and black lines downhill tracks. Yellow lines are some popular lines I have skied before.

We were concern about the effect of wind on N aspects, thus we kept the option open to ski a south aspect slope to the center-right in the topo map. The black line denotes a future line we dream about doing in the NEAR future.

We printed enough copies of this map with UTM coordinates (easier to read and work with) for each of the party members.

Unfortunately there are not many pics available from this area, and the various times I have skied there, visibility has been poor. But there are two pictures from www.splattski.com that shows our two intended destinations.

Lee Peak in the Left, Lookout Mountain in the right.

Gunsight Mountain

Next we googled pictures and review area using google earth.

Lee Peak in the center, Lake Lookout Mountain to its left.

This "aerial" google picture from 1994 shows the area we intended to ski ... pretty much the center left line below Lee Peak (Lee is in the center).

Angel Peak-Left, Lee Peak-Center, Lake Lookout Right.

Above another google view from the same area but created in 2005.

View to the North from the Top of Lee Peak. Gunsight Peak in the center.

Google view from the top of hat we plan to ski (Lee north aspect shoots). We skied the looker saddle in right of gunsight peak.

Next we check any information available through the resort and Wallowa Avalanche Center:

Wallowa Avalanche Center

WAC Backcountry Ski Reports

WAC - Anthony Lakes Link

Anthony Weather Station

From these links we found sufficient information for us to start building a "picture" on the conditions:

Temps durin the 24 hours prior to our visit were in the -9 to -4 Deg C with moderate winds from the NW trending to calm in the evening, cloudy skies and no precipitation.
Weather forecast of partially clouded skies clearing up in the afternoon, with moderate NW winds, and temps for the day in the range of -8 to -10 Deg C.

Based in the information we identified two concerns:

Wind slabs in top of depth hoar in a shallow snowpack.
Rocks and many buried obstacles.

Since a problem becomes a concern (a very "good" thing) when an action plan is developed, or "something is DONE about the problem". Otherwise, you might end up stuck in an escalator (figuratively speaking): Video of Two Stuck in a Escalator :)

We took note, and planned to pay close attention to aspects that might have been loaded with snow due to the moderate wind recorded Saturday, and the strong winds forecasted for Sunday. In addition we came prepared with "Rock" skis to address the buried obstacles concern.

By 8 AM we were at the resort, and after a routine stop to visit my friends with the Anthony Lakes Ski Patrol, we skinned up to Angel Basin. The snow was soft, but it was obvious that there was not sufficient snow to cover the very abundant granite!

A couple hundred feet below Lee Peak Summit we found a snowpack between 70 to 90 cm in depth. A snow pit in a 36-38 degrees gully with wind blown & new snow above old snow produced CTHQ2 results at 35 and 50 cm below the surface. Three CT failed at 50 cm, and one at 35 cm. Both layer interfaces (35 and 50 cm) consisted of weak layers composed of ~1mm near surface facets (NSF) crystals and mixed grains starting to round and sinter.

It should be noted that, similar to the snowpack in Copper Mountain - Idaho, we did not find basal facet layers (Depth Hoar - DH) at Angel Basin's North or South aspects.

A PST fracture propagation test at a 50 cm weak layer failed after a 40cm saw cut, suggesting that the weak layer & slab structure buried 50 cm below the surface have a fracture propagation potential.

Stability Assessment Quadrant

The Stability Quadrant shown above is a structured method use to assess slab avalanche stability. This method facilitates the review of the evidence we found of instability - "there is a high likelihood that a fracture failure will propagate if we were to find a weak trigger". Where we dig the pit the likelihood of a trigger was low (hard score), but as we continued touring and skiing, we were mindful about conditions and configurations that will augment the trigger likelihood, such as additional loading or thin spots in the snowpack.

The slip likelihood, is the last stage during an avalanche fracture failure, and it is a function of slope angle. The Q2 results suggest that there is a moderate likelihood of a slide once a fracture is initiated and propagated in the slope angles we tested. This information allow us to manage terrain angles and continue searching for more information (handpits, quick-pits) to avoid areas that might have a high likelihood (Q1 scores) of slip.

Finally, we identified structural weaknesses that assisted us in tracking the snowpack during the day; weak layer buried at 50 cm, a thin (less than 2 cm) weak layer with persistent grain types (NSF), and an identifiable slab (harder snow or slab in top of weak layer). As we travelled in Angel Basin, it was obvious that the slab structure was not present everywhere, and that was an important fact in the selection of slopes to ski.

During a slab avalanche there are three distintive phases; fracture initiation or nucleation (triggering), fracture propagation (due to propagation wave), and slide/slip of slab. Once the fracture failure occurs gravitation (weight of slab) and coefficient of friction between slab and weak layer (above gliding surface) takes over. This theory has replaced the now obsolete shear theory, and it has been validated through many studies. The stability quadrant shared above is a reflection of the NEW "Anti-Crack" fracture theory being applied to stability evaluation.

The ski down Angel Peak was fun, and not much later we were climbing up to Gunsight Mountain via the south face. The snowpack on this aspect was shallower (not a surprise) and "contact" with rocks during the ski down was much higher. :)

There are no pictures to share from this trip. The weather forecast did not materialized, and the skies remained obscured, with the mountain shrouded in clouds and fog all day- like skiing in a glass of milk!

I thought hard about not a posting a BC skiing area well away from Central Idaho Mountains. However, this is a great opportunity to share good practices with the Mores Creek Summit Skiers Community. This blog posting briefly covered trip planing and integration of weather in identifying concerns, as well as reviewing a methodology to asses snow stability.

Finally, The Elkhorn Mountains near North Powder and Baker City are abundant with BC skiing possibilities, that will delight Idaho BC skiers. One of the best advices I received MANY year ago was to ski in as many different snowpacks as possible to improve my avalanche terrain travelling skills. A vist by Idaho BC skiers to Angel Basin will provide opportunities to assist in the growth of your avalanche terrain travel skills as well.

Happy skiing this weekend!

Copper - Saturday 12.3.2011

2011-12-03T19:28:00.001-07:00

Saturday morning, Copper Mountain at Banner Summit woke up to a clear day with calm winds but very cold temperatures. The temperatures at 7400 on the western ridge leading to the top were -10 Deg-C. Snow surface temps were at the snow surface recorded -20 Deg-C. Also temperatures at 10 cm and 20 cm below the snow surface were -10 Deg-C and -6 Deg-C respectively. Most definitely gradients in excess of 1 deg-C per 10 cm! And it showed by the variety of near surface facets and advanced facets in the snow surface at all elevations and aspects. Surface hoar was not observed today in the snow surface.

Stephen at Copper Mountain, NEE 8600 feet before skiing recycled pow.

Snowpits at ~ 8600 feet of elevation at NEE (38 deg slope steepness) and SSW (28 degrees steepness) aspects did not revealed any weakness with multiple CTN and ECTX scores. At 8600 feet of elevation, NEE aspects had a snowpack depth (HS) of 80-100 cm, and SSW aspects had a HS = 50-60 cm. Both snowpacks had a progressive hardness from F (5-10 cm) to 4F to 1F. No basal facets (DH) were observed.

A quick-pit at NNE aspects, 8500 feet elevation, in a steep open meadow surrounded by trees, we were surprised to see a snowpack depth much shallower than expected, with HS = 40 cm. The whole snowpack in the mostly north aspect slope had turned into advanced facets. But the skiing was not bad at all!

One of the NEE slopes we skied.

Below a very short video of the slope shown in the picture included above. Too bad we could not get more footage - the cold temps messed up the cam, and it refused to cooperate!

The West, NW, and north aspects were severely affected by the wind with a mix of wind crust, and wind erosion features. These surfaces did not make for fun skiing!

However, with careful selection at S & SW aspects and NEE and E aspects it was possible to find fun lines to ski with 10-15 cm of soft pow. Below 8000 feet at aspects with any south, a nasty melt crust reared it ugly head. We learnt very quick to retreat to more treed slopes when skiing South aspects.

In general, coverage at Copper was adequate, buy it still requires some level of vigilance to avoid some buried obstacles.

There were other folks in the mountain, but we never ran into each other. I should note that it was a pleasure to run into Ralph (one of the blog contributors) for the first time this year at the Bench Creek pull-out. His tribe were heading over to Bull trout point. I will be looking forward for his report.

Mores Creek Summit & Google Earth

2011-11-24T06:39:00.001-07:00

Happy Thanksgiving!

Cailin, a good friend and member of the 705 Backcountry Ski Patrol, created a Google Earth KMZ file for the Mores Creek Summit area.

Below a description of the individual layers:

slope - <25 degrees not shown, 25-35 yellow, >35 degrees red (as in "green, yellow and red light" terrain).
smooth slope - same as above, with the underlying elevation data smoothed beforehand. It is worth comparing the two.
contour - 10m contour intervals for the area
all tracks - Overview map of Mores Creek area, previously published here.
convexities - Roll overs appear as grey areas
common routes - these are individual tracks from the above map, skin tracks shown in purple and ski lines in blue. Right click -> "show elevation profile" to explore length, steepness etc...

Note that you can overlay multiple layers at a time, as well as adjusting the transparency of each layer. There are definitely some limitations (especially small steep areas and convexities too "fine" for the data to see), and obviously no substitute for field observations and safe travel.

Mores Creek Summit KMZ file for Google Earth

Below few examples of the use of this utility for the lower Pilot and Lamar ridges:

10 meter contours

Slopes with 25-35 Deg (Yellow) and above 35 Deg Slopes (Red)

Slopes with North (red) and East (Yellow) aspects

Comments and feedback are welcome. It will allow us to further develop and enhance this layers for Google Earth, and incorporate other areas such as Banner Summit, Big Creek Summit, as well as Brundage/Bogus Ski Resorts "side country".

Big Creek Summit - Great Touring but No face shots yet

2011-11-20T20:29:00.001-07:00

Saturday 11.29.2011, at McCall, we had a very successful NSP Southern Idaho and Eastern Oregon Avalanche Instructor conference. Many participants across the region showed great enthusiasm, and we ALL learnt a lot about winter weather, snotel, Avalanche Fracture Mechanics, Decision Making, and reviewed NEW concepts about Avalanche Rescue. Special Thanks to Julie and Jeff from the Boise NRCS (the Idaho SNOTEL guys). Their Winter Weather 101 course and SNOTEL workshops were "facet-nating"! :)

The Event concluded with a tutorial on how to apply the Anti-Crack theory in the evaluation of avalanche instabilities. This theory continues to gain popularity among Avalanche professionals as field data supporting it continues to accumulate, and the Shear Failure Theory is abandoned for its serious inconsistencies explaining propagation and effect of slope angle. A sample slide of the Stability Quadrants resulting from the Anti-Crack theory is included below:

And to conclude this event, Dave Bingman from the Payette Avalanche Center and Keith Stebbings from Eastern Oregon's Wallowa Avalanche Center shared the centers accomplishments for Winter 2010-2011. They also previewed this upcoming season exciting new products and outreach programs.

After a very busy Saturday, some of the 705 Backcountry Ski Patrol spent Sunday touring the Big Creek Summit area East of the Warm Lake Road. It was a wonderful day, with a very cold start, but warming up nicely later in the day.

Stephen, Brad, Joe - Big Creek Summit

The snowpack depth was generally uniform with a depth ranging from 40 to 50 cm. Of course, not enough to cover deadfall and rocks, but sufficient for an splendid day of touring. After the storm left the area Saturday night, and the skies cleared up, the snowpack released its long wave radiation (infrared spectrum - heat) to the very cold dark sky. The humid air from the storm immediately above the VERY cold snow surface could not retain the water molecules. This is due to the reduction in molecular kinetic energy that reduces the intermolecular spacing in the air. Thus, the water vapor molecules, having no place to go, are deposited as "Surface Hoar". This SH was widespread and it was present at all aspects/elevations during our tour. The only exception was on treed areas, were the dark night sky was blocked by the trees.

During the day we observed also the formation of "Near Surface Facets"(NSF) at West and South aspects due to the cold snow and the warm afternoon. Much later in the day, at lower elevations and south aspects, we noticed the formation of a melt recrystallization NSF. WOW! SH, as well Diurnal and melt recrystallization NSF in a single day. But it does not ends there, as expected there were some (not too much) depth hoar (DH) crystals at the bottom of the snowpack.

In an attempt to anticipate instabilities during the next storm (Wednesday), Loaded Column and Shovel Tilt Tests identified a sensitive layer buried 4 cm from the snow surface. The layer consisted of NSF and precipitation particles (stellars and columns). It is possible that this layer was formed as temperatures plummeted late Friday November 18th, additional snow was deposited later on Saturday. This can be easily detected from the graphical snotel data for precipitation and temperature.

Big Creek Snotel Data

Notice that similar temp/precip can be observed at Banner summit for the same time interval.

Banner Summit Snotel Data

The buried NSF buried layer, as well as the surface hoar present, can be of concern if the weather delivers sufficient snow this wednesday to load the weak layers.

60-70% Probability of more than 15 cm for Wednesday 11/23/2011

The forecast for the next storm affecting Central Idaho is for a 60-70% probability of more than 15 cm of snow. We will have to keep an eye on precipitation intensity, total amounts, and particularly wind!

Furthermore, there were many "wumpfs" today as we skinned up. We believe that there were the result of collapsing snowpack as it sintered and gained cohesiveness (became slab), and not an indication of basal instabilities. The snowpack at the places we toured (6,000-7200 feet) had very little to none depth hoar. But as we get more snow (upcoming Wednesday) and the snowpack is loaded, I cannot stop thinking if these collapses can indeed trigger releases at the SH or NSF buried weak layers.

This next storm cycle will require a lot of our attention. And we all want to do pow turns, but it will be prudent to keep those angles shallow. Keep in mind that there are plenty of rocks/deadfall as well as the SH and buried NSF. Act conservative!

Christmas Present Ideas for Backcountry Ski Tourer

2011-11-17T04:09:00.001-07:00

I hope this message is shared by fathers, mothers, sons, girlfriend, or wife searching for a GREAT present for their love ones that happen to love to spend time in the sidecountry or backcountry during the winter months. This is the time when we become desperate for that elusive gift. I will include below some ideas of MUST have gear:

Sight-through Clinometer:

I noticed that the Brunton is priced at $74.59 - WHAT a DEAL!

AMAZON Link for Brunton Clinometer

A slightly cheaper option but very functional, and you get a compass (must have item) is priced at $45.55:

Amazon Link for Brunton Compass/Inclinometer

And finally a NEW item in the market with a very competitive price at 34.99:

Amazon Link for NEW Brunton Avalanche Inclinometer

There are other more expensive options, but I strongly recommend owning one of the above. For those that have are lucky to be love by the winner of the powerball I will include below the "Cadillac" of the clinometers:

Amazon Link for Haglof Clinometer

Magnifier for snow crystal identification:

STOP looking around, search no more, this is the best deal so far:

Amazon Link for Carson MA-30 Magni Scope Pocket Microscope

But if you get the scope, why not getting the BEST crystal card available? I do not recommend metal crystal cards - it is very hard to keep them from melting snow grains.

Amazon Link for BCA Crystal Card

Snowpit Technologies "Snow And Avalanche Field Notebook, 3rd Edition":

This is fantastic snow journal will keep your love one safe. It will help him/her to keep track of snow and avalanche conditions. It also has a lot of great information about stability tests, and other critical information. it is priced at $25.

Link for SWAG Field Book

Most likely your love one already has a Two-antena Transciever, a metal shovel with extendable handle, a 3 meter probe, and a snow saw. If not, what are you waiting for? Or if the probe or shovel have many miles or are reaching 10 years - go ahead an buy NEW reliable gear. Please make a note on buying a shovel with extendable handle, the new excavation techniques for avalanche rescue benefit from this feature.

A note on snow saws, I recommend a snow saw that can cut wood in an emergency. A nice feature - my preference - is the option of connecting the saw to poles available in the BD snow saw.

Amazon link for Black Diamond Saw

Snow Cord:

As we continue to educate backcountry users to use extended compression columns for snow stability evaluation, it is much easier (and fun) to use a snow cord to isolate the 90x30 cm snow columns:

Amazon link for G3 Cord

Avalanche Books:

Finally, the latest edition of Bruce's book has been updated, and it FUN to read.

Amazon Link for Staying Alive in Avalanche Terrain

Another book I strongly recommend is Snow Sense 5 Edition. I could not find a link at Amazon that will guarantee the 5th edition. And you want to GET this last edition! Thus I recommend that you use the following e-mail for ordering the book:

snowsensebook@gmail.com

If I come out with other gift ideas, I might come back and edit this posting.

More Snow Forecasted for Next Weekend -11.15.2011 Update

2011-11-15T05:33:00.001-07:00

The Wx Forecast discussion from NOAA for our area is looking promising. more snow is coming!

Below an excerpt for Today's Long Term Wx discussion:

FRONT WILL EXIT TO THE EAST ON FRIDAY...BUT SNOW SHOWERS WILL PERSIST AS THE UPPER LOW DIGS OVER IDAHO. CENTRAL IDAHO MOUNTAINS LOOK TO RECEIVE THE BRUNT OF THE SNOWFALL. UPDATED SNOWFALL FORECAST /STORM TOTAL/ PUTS 5 TO 8 INCHES OF NEW SNOW IN THOSE MOUNTAIN VALLEYS...AND UPWARDS OF 18 INCHES ON HIGHEST MOUNTAIN PEAKS.

There is a nice tool I like to use, and that I shared last season with my blog friends. The probabilistic model results for this Thursday through Friday period is included below:
HPC Experimental Probabilistic Winter Precipitation Guidance

48 hour Probability of SNOW Accumulating more than 12 in. (30 cm)
for period ending Friday november 18th

BC Skiing this upcoming Saturday promises to be good at places where a base has been building due to last weekend precipitation event. Notice that in the chart above, the West Central and Boise Mountains have a 50-60% chance of more than 30 cm of NEW snow.

As you are heading out this weekend, make certain that you keep in mind the following pointers:

NEW batteries for transceiver, and headlamp in you pack. Better, practice with your transceiver this week. No need to bury it, have a friend/wife hang it indoors above sight line and look down during the search.
Inspect your aluminum shovel with extendable handle. Al shovels tend to develop stress crack, replace if you detect any. If you have a plastic/lexan shovel use it for dog poop or other tasks - then BUY a new shovel. Check your 3 meter avi probe. If you have anything shorter, help local businesses and BUY a new probe!
Make the habit of checking Wx and AVI forecasts, links are provided on this BLOG!
Check your 1st aid kit and Emergency gear such as fire starting material, bivy sack, puffy coat, extra gloves, energy bars, leather-man tool.
Take a close look at he bindings condition ... you don not want to have a failure while touring.
Get a SWAG Blue Book or journal for Wx/Avi obs. Start this weekend by looking at the snowpack and recording observations.
Verify that your INCLINOMETER is in your ski pants or coat! If you do not have one - BUY ONE PRONTO!
Print topo map of area to you plan to tour this weekend, study it, think where you want to go, and stash it in your coat. If you are feeling nerdy, study benefits of UTM coordinates.

As some of you know, the avalanche danger early in the season is accentuated due to the shallow snowpack and formation of basal facets (depth hoar) at the bottom of the snowpack. In addition there has been a lot of wind transport and windslab formation during the last weekend two storms. This upcoming Thursday/Friday snow loading event will surely stress the snowpack!

This is a good time to visit those low angles slopes we always wanted to explore, and/or time to go on outing to verify overall equipment performance - check skins, new boots, backpack, ... TAKE it EASY!

PS:

This Saturday - November 19th, there is a NSP instructor Conference organized by the South Western Idaho and Eastern Oregon Region NSP Avalanche Education Team.

This event is open to the public.

The event is at the Best Western in McCall, and starts at 9 AM. We hope to finish by 4 PM. There will interesting talks about Snotel Tools, Winter Weather 101 workshop, Decision Making and Avalanche Fracture propagation, talks by the region Avalanche Center directors (Payette and Wallowa Avalanche Centers), and the best part; you get to meet folks interested in advancing avalanche eduction in our area.

Copper Mountain - November 13 2011

2011-11-13T22:12:00.001-07:00

This last weekend, two winter storms jump started the Backcountry skiing season in Idaho. After snotel encouraging reports of new snow overnight at Banner Summit, it made sense to pay a visit to Copper Mountain.

Idaho City Visitor center on the drive to Banner Summit - Copper Mountain

For Copper Mountain North-West, West and South aspects, at 7000 feet the snow depth was 20-25 cm, at 8000 feet 25-30 cm, and less than 20 cm above 8500 feet due to wind transport.

The new snow was ~10-12% dense, and it will make a great "starter" base. In fact the new snow was exceptionally well distributed below 8000 feet, and if we get the additional snow forecasted through this week, and if we very lucky to exceed the 50 cm total snow depth, the skiing lower in the mountain might be the best November BC skiing at Banner Summit for the last 5-6 years!

However, I need to emphasize that if we do not get NEW snow, the skiing at Copper Mountain will remain dangerous due to MANY buried obstacles, as it can be observed in the video included below:

Copper 11.13.2011 from Santiago Rodriguez on Vimeo.

In order to maximize "float" and not destroy my Wateas skis with rocks, logs, frozen dirt, I resisted the temptation to ski steeper terrain and mostly skied low angle slopes.

The coverage below Copper Summit was poor and I decided not to summit. There is not enough snow, and it would have required walking down. It is likely that most of the snow from the South face was blown into the N and NE slopes facing the Sawtooth valley.

Coper Mountain Summit behind the fog.

Not surprisingly, above 8000 feet, where the new snow was sitting in top of facetted snow and/or wind driven snow from Saturday windy front, it was easy to hear the snowpack whumpfing (collapsing!). Also, in the flats at 7000 feet sporadic whumpfs were produced too due the formation of soft slabs (snow settlement and snow grains rounding & sintering resulting in densification of the new snow).

Be mindful of buried depth hoar early in the season due to shallow snowpack. Whumpfing suggest that there is fracture propagation propensity, and that a human is likely to trigger an avalanche if the terrain is steep enough.

By the way, avalanches at Alta-Utah became a problem this Sunday afternoon. And another rider died at Snowbird:

http://www.sltrib.com/sltrib/news/52907844-78/avalanche-resort-kobernik-ski.html.csp

http://www.sltrib.com/sltrib/news/52906292-78/avalanche-kobernik-storm-area.html.csp

After a wintry storm made driving dangerous Sunday morning, an unstable snowpack made skiing hazardous Sunday afternoon.

Four avalanches were reported Sunday afternoon, with one person suffering a leg injury, said Brett Kobernik, an avalanche forecaster with the Utah Avalanche Center.

Three of the avalanches were definitely human-triggered, and it appears likely the fourth one was as well, according to Kobernik.

All four were in the Alta Ski Resort, which has not yet opened for the season. Skiers need to treat the resort as a backcountry ski area because there are no ski or avalanche patrols, he said.

The layer of snow that fell in October is weak and sugary and now covered with heavier snow from the recent storm.

Announcing SnowGeek.org

2011-10-09T17:15:00.007-06:00

Today it brings me great joy to announce that SnowGeek.org is now live!

For those that are unaware of what the project, read on.

SnowGeek is an ongoing project whose mission is to achieve excellence in education, data analysis, and resource compilation. The goal is that by offering advanced, but user friendly features to analyze data and compile resources, SnowGeek creates a community that facilitates discussion about snow science and avalanche education.

At launch, SnowGeek includes the Home, Blog, About Us, and Contact Us Pages, but that won't stay true for long. Very shortly after launch the Community page will be added which at the moment will include a forum for discussion and hopefully much more! If you have ideas please leave feedback by going to "Contact Us".

Following the addition of the community page, I will start work on creating the primary features that SnowGeek will eventually offer: The Data Center, The Education Center, and The Resource Center. The first feature to be created will be The Data Center and should be ready by the start of the winter. The goal is that this winter you will be able to enter your field observations to save them, analyze then, and contribute to a database open to researchers.

SnowGeek will also be following hot news in Avalanche Education and Snow Science so bookmark it now! You can also subscribe to the SnowGeek RSS feed by clicking on the RSS button on the top right of this article, following @SnowGeekOrg on Twitter, or adding SnowGeek to your Facebook by clicking Here

Be sure to check out the About Us page and consider donating to SnowGeek

Sincerely,

Pedro Rodriguez

SnowGeek Founder

2011-09-27T20:53:00.000-06:00

This winter is looking very promising again this year, with a recurrent La Niña. Below an excerpt of the outlook posted by NOAA early this month:

La Niña, which contributed to extreme weather around the globe during the first half of 2011, has re-emerged in the tropical Pacific Ocean and is forecast to gradually strengthen and continue into winter. Today, forecasters with NOAA’s Climate Prediction Center upgraded last month’s La Niña Watch to a La Niña Advisory.

NOAA will issue its official winter outlook in mid-October, but La Niña winters often see drier than normal conditions across the southern tier of the United States and wetter than normal conditions in the Pacific Northwest and Ohio Valley

A link for the complete outlook is included below:

NOAA’s Climate Prediction Center: La Niña is back

EL NIÑO/SOUTHERN OSCILLATION (ENSO) DIAGNOSTIC DISCUSSION

Now to the good NEWS. The outlook for Nov/Dec/Jan included below shows above average precipitation early in the winter:

A similar trend is also present for the middle of the winter (Dec/Jan/Feb 2011):

The precipitation mellows down later in the winter (Jan/Feb/March 2012):

In addition the temps for early winter are expected to be average, but by mid winter (Jan/Feb/March 2012) the temps are expected to be below average:

So in our area, La Niña will be driving probability of higher precipitation and lower temperatures. These charts can also be found with probability values at:

EXPERIMENTAL TWO-CLASS SEASONAL FORECASTS

As we get closer to winter, there will be additional information related to climatological trends. Particularly on the strength of La Niña event.

Chago

Chago is back from South America!

2011-09-25T20:40:00.000-06:00

I just returned a few days ago from my one month migration to South America to teach avi courses and ski tour the wonderful terrain the Central Andes and Northern Patagonia has to offer.

Below some teaser pictures to get you thinking about the Northern Hemisphere winter.

Details on the pictures can be found in the following link:

Chago Southern Hemisphere Winter Blog

Enjoy the the blos posting for South America!

Chago

Roaming the Idaho woods again ...

2011-03-21T06:45:00.000-06:00

I am so glad to be back BC skiing the local mountains. After spending weeks in the mountains of Eastern Oregon and Nevada in avi courses it really feels good to relax and ski tour close to home.

After preparing french toasts for the family, I had a late start and left Boise by eighth thirtish. I was surprised to find the Freeman pull-out vacant. At the switchback, as I was about to start skinning up, Gary and Kelli stopped in their car and offered me a much appreciated company. I continue breaking trail, until they caught-up with me at the top of the meadow, just before the final ramp to the top of Freeman.

During my climb, before my friends caught with me, I had time to clear my head. 2011 has been a year of change; I left HP after 24 years and started working for Transform Solar, I dearly miss touring with Pedro after he left the nest for Berkeley, and I naively packed my schedule with avi course through the whole season. I missed great skiing in February in our area, but I spent countless hours in the Elkhorns above the Baker Valley in Oregon, and I was initiated in March to the Schell range in Eastern Nevada - a true "wild west" experience!

As Gary and Kelli joined me, I realized how lucky and fortunate I am. Without the support from so many fiercely loyal friends, it would have been an impossible year.

And there I was, BC skiing with friends, and meeting new ones (Brian and Jimmy).

There was a combo of sun, rain, and wind crusts at all elevations and aspects. But the wind moved enough snow to create many pockets and lines of very skiable boot high pow. The trick was to "choose wisely". Choosing poorly would have taken you into the instructional snow realm.

The only concern for Sunday was weak layer buried 50-60 cm with moderate stability results. But the snowpack at Mores Creek Summit to large extent seems to be sintering well. I suggest to keep an eye above 7500 feet for a very thin rain crust above dry snow, that has developed "Near Surface Facets" (NSF) below the crust. This surface crust was quite spatially variable, thus it will meant checking every slopes above 35 deg before jumping into them, assuming we get the new snow forecasted for early this week.

The coverage at Mores Creek Summit is extremely good, above average. The area is in great shape late winter pow skiing, and the mid April to May corn season.

One final note, anybody is welcome to post to the blog. Just send a comment asking for access. All it requires is the willingness to share observations, stories, essays, pictures, videos, or relevant data about West Central Idaho backcountry skiing. The only requirement is that it should be a community building contribution. I realize that some folks have a high desire to contribute, but are timid to contribute for many reasons. I promise that many of us will appreciate your comments .... c'mon take the leap!

Chago

The Glades - Pilot Peak - 2.6.2011

2011-02-06T22:51:00.000-07:00

After a somewhat disappointing January, the Idaho West Central mountains are about to receive new snow during the next 48 hours. Check the chart with probabilities for more than 2.5 cm for the next 24 hours.

For more REALLY cool NOAA products visit the website for the "HPC Experimental Probabilistic Winter Precipitation Guidance" included next:

http://www.hpc.ncep.noaa.gov/pwpf_24hr/wwd_24hr_probs_sn.php

Wanting to just get out to the Idaho backcountry and check the surface snow conditions before the new snow comes, I went for a short tour to Mores Creek Summit. Considering the wind, snow surface, and temperatures it was no surprise the lack of surface hoar formation or "Near Surface Facets" in the snow surface - that was good news. The bad news was that surface crusts can be found at all elevations and aspects, even the northerly aspects. In addition, the surface crust is undermined by 10-20 cm layer of "near surface facets".

The skiing was high in instructional value today. At lower elevations with E or SE aspects a supportable crust was grippy and more fun than the zipper or thick breakable crusts of N and NE aspects.

A snowpit at 7300 feet on a 30 degree slope with a NE aspect revealed the following profile:

Two layers reacted to compression tests at 20 and 50 cm depth. It is a good practice to first perform stability tests before generating a snowpit profile. The only reason I carefully profiled the snowpit today was to make point how challenging it is to identify the layers of concern without compression tests when there are many crusts present. This point is exemplified in the next photo:

The right hand column (behind the shovel) is the top 20 cm slab, and the left hand the bottom 30 cm thick slab buried 50 cm under the snow surface. These slabs were cohesive enough to stand vertically after completing the "Propagation Saw Test" (PST). From the snowpit profile alone it would had been difficult to identify the cohesive slab and weak layer/interface.

The stability results at the two layers of concern suggested:

Moderate Trigger Likelihood - CT12 @ 20 cm, and CT19 @ 50 cm.
Low Propagation Likelihood - negative PST and ECTN.
Moderate Slip Likelihood - Q2 results.

Moderate results are what it is typically characterized as yellow conditions, meaning that we need more data and it is prudent to proceed with care. The crust structure at Mores creek appear to be widespread and uniform, and the ice ring around trees are connected to the multiple existing crusts. This is one of those times where the snowpack is well anchored. In addition the heavier crust at East aspects make difficult to trigger the two weaknesses at 20 and 50 cm. This could change with rapid loading (big storm or wind loading) or rapid warming, both of which are NOT expected or forecasted during the upcoming week.

I have been experimenting for few years with IR thermometers to speed up the temperature profiling of a snowpit. The chart included below was generated form IR thermometry. This information is key to determine what type of metamorphism is active (rounding/sintering or facetting). The next chart for various temperature recordings documents a gradient close to the 1 degree Celsius per 10 cm in the top 20 cm of the snowpack. As commented before, below the surface crust a layer of small NSF (near surface facets) was observed at all elevations with E, NE, and N aspects.

Based in the above temperature profile the temperature gradient between 20-70 cm is much smaller than 1 deg-C per10 cm. This suggest that the snowpack is gaining strength due to rounding (rounding of facets), sintering (development of inter grain necks) and settlement (compaction due to gravity).

Included below, photos of the surface hoar crystals buried 50 cm unders the snow. These surface crystals have undergone some level of rounding, but there are just too BIG (excess of 4 mm) to sinter or develop necking with other grains.

The large and rounded SH (surface hoar) crystal included below were loose and noise in the plastic snow card. I included the pictures to assist other is identifying this difficult to detect layer. The lack of propagation potential of this layer during today's stability test, rounding of the SH crystals, and the fact that the SH layer appear to be collapsed, suggest that this weak layer is not active. I still recommend to continue to monitor this layer during the next weeks. There could be slopes at higher elevations, or very steep slopes where the snowpack has not yet collapsed or stabilized the SH layer, and it is waiting for a human trigger.

Finally, Pedro (my son) has been working on a NEW website to collect snow stability data. He named the website BDC (Backcountry Data Center). Feel free to visit the facebook page showing the progress of this website to be unveiled next season 2011-2012. He welcomes any input you might have.

BDC Facebook Page

Chago

Pilot Peak - January 15th 2011

2011-01-16T08:08:00.001-07:00

Yesterday was Pedro's last day of Idaho Skiing for this season before his return to Berkeley. We were concern that the snow conditions were going to be "uncooperative" and that skiing was going to be highly instructional. Man, were we wrong! Skiing at Pilot Peak was much better than we expected. The snow was heavy but creamy. The top 20 cm were soft (fist hard), and if you were gentle on the skis and skied long arcs at speed, skiing was a lot of fun. The trick was to keep the skis floating in top 20 cm of snow. But if you allow your riding tools to sink ... well it was not hard to end up doing face plants.

In many places above 6500 feet of elevation the new 35-45 cm of snow is resting at N, NE, E aspects above a layer of "surface hoar" crystals. This layer was sensitive today with numerous massive "whumpfs". Interesting enough we did not detected surface cracks during the multiple collapses (whumpfs).

Stability assessment at N, NE, E aspects between 7000-7700 feet revealed easy triggering and propagation likelihood:

Multiple CT1Q1 (SC) at 45 cm (SH 4-5 mm)
ECTPQ1 SC at 45 cm (SH 4-5 mm)
PST 40/100 (End) at 45 cm (SH 4-5 mm)
More than a dozen of Easy Hand tests at N, NE, E aspects elevation 7000-7700 feet. Some of the Hand Test failed during isolation in pockets with very well developed surface hoar crystals, and easily slided downhill!

The term SC above refers to the collapse of the slab above the weak layer during the test. The SH term denotes a surface hoar weak layer with large crystals in the 4-5 mm range.

Observations and testing at SE aspects did not reveal instabilities present and the buried surface hoar was NOT detected. We choose to threat these slopes as suspected and keept angles below the 32 degrees of steepness, limiting our mobility (switching to the Glades Ridges) when skiing the SE aspect slopes of the long and fun Knob ridge.

The ECT (Extended Column Test) ans PST (Propagation Saw Test) are tests that allow us to gain understating on the propagation potential of fractures. You will find descriptions for this tests at the following link:

Snowpack Observations Guidelines - AAA

Another party reported RB2-Q3 at a slope with East aspect at 7900 feet.

Two natural release were observed by our party at a NNE slope with 34-36 slope angle at the starting zone. They were classified as SS-N-D1.5-R3-N and ran for 100 vertical feet.

SS means soft slab
N stands for natural release
D1 describes destructive power, a one suggest that ran less than 10 meters. A D2 can bury a skier.
R3 quantifies the distance it ran, for an scale of R1 to R5, with R5 as maximum.
The second N denotes that the avalanche involved NEW snow.

If you are interested in reviewing and/or familiarizing with the classification and recording of avalanche observations please refer to the following link:

Avalanche Observations Guidelines - AAA

Yesterday was easy to find instabilities in the snowpack at Pilot Peak. The obvios red flags were: collapses, warming temperature trend, and recent loading event (45 cm of NEW snow). To this list we can possibly add ratings of considerable or above on the the regional forecasts (HIGH for Payette Forest and West Mountains, and Considerable for the Sawtooths).

It was comforting to observe all parties exercising good judgement and managing angles during yesterday ski outing. Surface Hoar instabilities are notorious for avalanches getting triggered at shallower angles (lower 30's), and as far as I could tell skiers and riders were skiing terrain that did not exceeded 30 degrees in steepness.

Todays's forecasted rain up to 8000 feet, and continued warm temperatures above the freezing level will make skiing less attractive (Movie Theater Time!), but in the meantime it is likely that in the long term it will assist in stabilizing the snowpack.

Chago & Pedro

Big Creek Summit - East Side - January 3 2011

2011-01-04T00:11:00.001-07:00

Today Pedro and I ski toured and skied in the Big Creek Summit area.

This years is special due to the above average snowpack depth and cold temperatures, thus it is possible to ski lines with some South aspect, and not run into "instructional" snow. It has been about 3 (maybe 4) years since we skied the East Side of Warm Lake Road next to Big Creek Summit.

Google Earth is great tool for trip planing. Trip planning is one of the most important elements to acquire knowledge from the area to be toured and skied. Study of satellite views and topo maps augment the safety of a trip, and provide familiarity with the terrain to be travel.

The next Google Earth view of the area we skied today shows the open slopes with less vegetation, and better skiing. At the bottom of the image, the Warm Lake road is visible, as well as the parking pull-out (at 6150 feet).

The topo map included shows the short tour to a sub-summit, that provided some spectacular views. In red the ski runs we did today. We had limited time to ski more terrain. It was a short day since I had to drop my son at school in the morning, and pick him at school by 3 PM.

The ski runs with West and South-West aspects had 20-30 cm of Diurnal re-crystalized snow (facets!) that were distinctly "pleasurable" to ski. The ski run with North-West aspect consisted of preserved "old" pow snow, dense and creamy. Enjoy the video of Today's skiing!

The terrain we toured today rarely exceeds the 32 degrees of steepness, although there are some terrain traps at the creek bottoms that demand some attention. Anyway, we wanted to contrast the stability assessment with mores Creek Summit snowpack. As the Avalanche Centers (Payette and Sun Valley) have been stating, we found a surface hoar (SH) layer buried 50-55 cm from the snowpack top. The next picture, next to my fingered glove, you can identify some SH crystals in the sliding surface.

The compression test results were hard and the fracture propagation during the Extended Column Test (ECT) was arrested before reaching the end of the column. However the failure had a sudden collapse character with a clean sliding plane typical of Q1 character. A quick snow pit documented a snowpack with structural weaknesses:

Weak Layer (SH) in the top 1 meter of the snowpack.
Weak Layer is a persistent type grain (PGT) - Surface Hoar
Weak layer grain size is 1 mm larger than the slab grain size (2-3 mm vs. 0.5 mm)
Weak Layer is one step softer than the Slab hardness (Fist vs. 1 Finger)
Weak Layer is thin (less than 10 cm)

Most snowpacks associated with avalanches have at least more than 3 of the above structural weaknesses. The snowpack at Big Creek Summit had five LEMONS! In addition, the stability assessment found evidence of instability, the Q1 test result. It might be hard to trigger and propagate a slide, but a slab avalanche with half a meter of depth can easily ruin your day. Be mindful of wind loaded slopes or places were the snowpack is thin allowing to easily trigger the Slab/Surface Hoar snowpack weakness.

The buried "surface hoar" layer was not detected by us at the slopes we skied at Mores Creek Summit last December 30th.

We snapped a good number of digital pictures of VERY large surface hoar crystals recently formed above the recent snow. Their sizes varied from 2 mm to very large monsters, as you can see next.

But most slopes had the 3-5 mm surface hoar shown in the next pictures.

The SH deposition was extensive at ALL of the slopes we travelled today. We will have to be vigilant once this dangerous layer is buried. And remember that avalanches associated with SH, run at much more shallower angles (30-34 degrees of steepness) when compared with other weak layer structures.

Chago

Freeman Peak - December 30th 2010

2010-12-31T01:25:00.000-07:00

Freeman Peak skiing was exceptional today!

We observed numerous D1-D1.5 (small) size crown fractures from the instability cycle that resulted after yesterday storm. Most of the fractures were in terrain features with slope angles in the neighborhood of 36 degrees. Stability evaluation in the area we skied suggested: 'Easy' triggering (CTE), with moderate slip likehood results (Q2), and no evidence of propagation. However, be aware that fracture propagation tests are questionable under soft slab conditions.

In addition, after a brutal team effort in trail breaking, none of us observed any fracture/crack, propagation, or wumpfs -NO evidence at all of instabilities. Hand pits at various elevations confirmed same results as the snow pit results - the new snow is bonding very well at Freeman on the elevation range (5900-7200 feet) we skied today. But CTEQ2 (X2) results remind us of being vigilant through-out the day, and avoid snow that has become cohesive or "slabby".

Today's moderate winds did not affected the skiing or snow below the 7200 feet with NE and E aspects. The snow at ridge tops developed windslabs, but the wind was loading the SE & S aspects. The only time we observed any evidence of propagation potential was 20 meters or so below an Easterly aspect ridge line with cross-loading. We avoided those pillows.

By the way - it is hard to believe but the recent rain/melt crust is buried 90-100 cm down! Last time I skied Mores Creek Summit Area (Lamar Headwaters) there were 30 cm of pow above the crust, thus at mid elevations the latest storm left behind up to 60 cm of NEW snow.

Chago

PS: Erik, Rick, Andy - it was a pleasure to meet you today! THANKS for helping with the trail breaking.