Avalanches: Large natural spanning most of M face (NNE aspect); large natural running the length of the ridgeline on skier’s right side of the bowl we skied (ENE aspect); large natural below tree line along skin ridge (E aspect) that is obvious from the highway, with debris piles in the exit gully. Lots of others, including some small but surprisingly low angle pockets, along Gibson Ridge.
Weather: Clear skies, moderate NW wind, temps near 0F at start warming into teens by mid-morning
Snowpack: North aspects wind scoured and punchy to rock hard. Some collapsing and cracking on 30+ degree north-facing slopes near treeline. Skied variable snow in the main east-facing bowl from the high point above M face. Lots of wind impact in the bowl; rock hard but smooth in skier’s left half to punchy sastrugi in the skier’s right half.

Avalanches: See video. One fresh looking hard slab looked like it failed in the past few days due to cornice fall. HS-NC-R2-D2.5-O. Slab was pencil hard, up to 140 cm thick, averaging ~60 cm. Failed on 1mm rounding facets, 4F hard (I think Jan 14 facet layer), and stepped down to the ground in places, which was only another 30 cm deeper or so.
Observed several dozen additional undocumented persistent slabs from 2/1 cycle, on a variety of aspects and elevations, D2 to D2.5 in size. Most appeared to run mid-pack (Jan layers), but some went at the ground on depth hoar. Regardless, crown sizes were all pretty similar; there wasn’t much of a midpack between the January layers and early season depth hoar here.
About 5 small loose wet ran naturally either today or yesterday. S to W aspects NTL.
Weather: Light winds. few clouds, warm temps
Snowpack: Surface is a trashy mix of wind board, sastrugi, and meltfreeze crusts.
Got one small, soft collapse below treeline on a flat slope, and 5 or 6 loud collapses on a NW facing bowl N/ATL, radiating up to 40 feet with shooting cracks. These were on discontinuous slabs ~1-1.5 ft thick over depth hoar (3-4mm, fist hard) near a windscoured ridgeline, ~30 degree slope. Would expect the slab to become more continuous lower on the slope.
Didn’t get onto anything too steep and sunbaked, but water wasn’t moving beyond the top couple inches of the surface on 20-25 degree slopes with southwesterly tilts.

Crowns from 2/1 cycle. East face of Gothic.

Crowns from 2/1 cycle. SE aspects on White Mtn

Crowns from 2/1 cycle. S aspect on White Mtn

Crowns from 2/1 cycle. SW aspect on White Mtn.

Fresh looking crown on NE aspect above Perry Creek. Looks like it failed in the past 3 or 4 days. HS-NC-R2-D2.5-O.

Fresh looking crown on NE aspect above Perry Creek. Looks like it failed in the past 3 or 4 days. HS-NC-R2-D2.5-O.

Crowns from 2/1 cycle. W aspect above Perry Creek

Crowns from 2/1 cycle. W aspect above Perry Creek

Crowns from 2/1 cycle. NW aspect above Perry Creek

Multiple loud collapses and shooting cracks on a NW aspect N/ATL

Avalanches: Looks like a naturally triggered Avalanche of Redwell Basin.  **CBAC note: first observed 2/4/16**
Weather: Sunny warm morning. Snow got nice and soft by 9am in the sun.
Snowpack:

Avalanches: very top of mt emmons, my 36 pound dog got too close to the edge of the cornice. a school bus sized chunk broke loose. nobody was caught or hurt and the dog is fine. sorry we broke yer cornice……
Weather: Sunny, warm
Snowpack: variable

Avalanches: Most of the major paths around here ran naturally 2/1, but there were still some slopes that looked like they hadn’t. On the more northerly tilted slopes that had slid, the structure is faceting back to 10-15cm of very soft 1mm facets over crusty bed surfaces, and we were able to skier trigger small and predictable facet sluffs.
Weather: Clear, warm temps. Moderate ridgetop winds, no transport observed on peaks.
Snowpack: See video.  January 14 facet layer (1.5-2mm, Fist hard rounding facets, found on E and NE aspects, 60 to 65 cm deep, under slabs up to 4F+ or 1F-) and Jan 29 surface hoar layer(s) (found on NE aspects, 35-40 cm deep) all still consistently propagating in extended column tests. Repeatable ECTPM results on both layers in all pits. On east aspects the Jan 29 interface is a thin crust with ECTN failures. At noon on a due east slope, ~35 degrees, Tsurface was 0*C, T20 was -3*C, and the Jan 14 facet layer was -4*C 65 cm deep. The top 2 cm was very wet, the next ~8 cm was moist. Dry through the rest of the pack. On northeast aspects, the surface is dry and quickly faceting, with both 1mm near surface facets and surface hoar forming.
No collapsing or cracking observed, although the lower angle terrain that we predominantly traveled on has a noticeably deeper and stronger snowpack than steep terrain because of the Christmas wall-to-wall flush.

Two surface hoar layers buried right next to each other, both produced collapsing results in ECTs

Two surface hoar layers buried right next to each other, both produced collapsing results in ECTs

Shaded paths that ran 2/1 in this area have small facet sluff concerns now, which indicates how weak they are if we see future loading.

Surface hoar and near surface facets growing on shaded slopes.

Weather: Moderate northwest winds at 13,000ft with a few guests on lower ridgelines. Clear sky and warm temps.
Snowpack: Traveled through lots of alpine terrain with only surface obs and quick informal tests. The most worrisome looking areas where old plastered wind slabs, and anywhere a big slope tapered near rock outcrops leading to a shallow snowpack that you could feel obvious persistent slab structure below. We used cation and avoided plenty of areas, and didn’t observe any obvious signs to instability where we traveled.

Northwest facing slopes above treeline are well worked over by the wind. Patches of textured cream with lots of firm texture and windboard. Hugely variable snowpack depth of course and plenty of slopes in extreme terrain looked like they could be in the 60-130cm range and likely harboring some form of persistent slab.

Probed around on some northfacing terrain at 11,000 feet that had below treeline characteristics. Ski pen was about 25-30cm and HS in the 180-200cm range. The bottom 30cm near the ground was a little punchy otherwise progressively harder layers is all you could feel via probe.

Southerly facing slopes also had lots of wind effect. With the same wind textured cream, wind board or firm wind texture scattered about. As snow surfaces started cooling in the afternoon a widespread thin crust was forming.

Avalanches: Had good views of southerly slopes in the higher peaks snow favored part of the zone. Saw very little wet loose avalanche activity. The south and southwest facing slopes off of Schuylkill Mountain were the exception. With several small loose wet avalanches failing on the steep slopes near rock outcrops.

Loose wet avalanches on steep south to southwest slopes. Schuylkill Mountain

Natural Persistent Slab that failed around February 1st. Westerly aspect around 11,000ft. Looked like it may have been triggered by a smaller wind slab failing higher up in the terrain.

Avalanches: HS-AB-R3-D2-O/G on 14lb airblast on 38º, west facing, shallow slope. 1-1.5m debris
Weather: Clear skies, intense solar, Above freezing at study plot (inversion) by 10:30-11am. Minimal wind at all elevations. One of those spring-like days.. High 36º
Snowpack: Stability tests in untraveled terrain in Rooster Rock area (south of Asia..) showed very poor structure, ECTV x2, ECTX, PST 30/130end on 20151211 depth hoar. The one extended column with no propagation was an interesting outlier?, after getting continuously poor results. Came back around with a 12£ ANFO airblast for same area with no result… bad shot plaement? False unstables?

Then went and poked into untraveled New World terrain… no results on all shots except shallow rock bank airblast, probably would have gone with lighter shot, but just happened to go on “stamp” Airblast. Average HS in krumholtz on upper half of new world has 200cm, but lower, steeper terrain is much shallower, more similar to rest of UUWW. Wet snow on SW facing terrain even in NW this afternoon.

East and south snow surfaces were moistening by noon.

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