Avalanches:
Weather: Light winds, no observed blowing snow but mainly traveled in protected areas. Mostly cloudy sky became overcast to obscured with s-1 snowfall in the afternoon.
Snowpack: More managing terrain for potential windslabs. NTL at the top of climax 15-30cm’s of new snow was resting on NSF. The new snow is getting close to becoming enough of a slab to have a more widespread problem at this elevation, but still additional wind-loading was necessary to create an avalanche problem. Jumping on one wind pillow produced shooting cracks for the width of the pillow but the slab didn’t budge on that feature.

BTL, the snowpack has potential concerns for when that elevation accumulates enough snow. NSF on northeasterly aspects and some facet crust sandwiches on more easterly aspects.

Avalanches: On a cross-loaded east aspect at 11,500 ft, I skier triggered a 12″ deep, 30 ft wide wind slab, which broke on facets between 2 thin crusts. SS-ASc-R1-D1-O.
Weather: Cold! Temps stayed below 0F at high elevations. Winds picked up through the day, moderate to strong out of the west, transporting snow near ridge lines. Overcast/obscured skies.
Snowpack: The most recent storm snow (~8″) appeared to be bonding well to the crusty interface (2/22). No cracking or sluffing observed, even in thicker drifted areas. On southerly aspects, there is a crust/facet/crust sandwich below the storm interface, which became more concerning (due to thinner, softer crusts) the closer we turned towards north half of the rose (such as E and W aspects). This could become an issue with more loading.

E-aspect-Barkmarker

Avalanches: none.
Weather: OVC skies turned X in the pm with light snow, mostly S -1, with a couple convective waves of heavier snow, light w/ moderate Gusts WSW, minimal snow transport, started increasing late afternoon. Cold temps Highs reached: 12F/0F
Snowpack: Very few signs of instability, with very minor cracking off the ridge in EBM, otherwise no signs of instability. New snow seems to be bonding fairly well to crusts. Double Crust facet sandwich (Feb 22 & Feb 19) on E,S,&SW with facets in-between, could become problematic and will need to be tracked. SBM, Flaming Ferrari/Sunny Shouder (HS 225cm): 15cm’s of new snow on top of 2cm MFcr (Feb 22) then 2-8 cm’s with 1mm Facets to the 25cm MFcr (Feb 19th). Ski pen going through Feb 22 crust in shady areas BUT NOT in Sunny Areas. LWW, Top of D&D (HS 100): 15cm’s of New snow on top of 1cm MFcr (Feb 22) then some .5mm facets before the Feb19 MFcr (6-10 cm’s). 2mm facets below the 19th crust but very rough and uneven. Ski pen going through Feb 22 crust. Lone Wolf had pretty equal distribution of new snow (20cm’s) and not really cross loaded, No Cracking. Minor pockets triggered in cross loaded rollover above LA Fadeaway and in Gerbil Shooter. Thread and Needle blown out up high with double crust. A fair bit of new snow (30cm’s) once you got mid slope. No cracking, minor sluffing.

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SBM-Flaming

NTL: Classic terrain management for windslabs. Testing the windslab boundaries near ridgline we triggered a 35-40cm deep slab while hiking up. This was an easterly aspect at 10,650 right at rideling. A few collapse where felt in the area previous to the triggered windslab. Mid February well developed near surface facets were the weak layer, under the most recent very soft crust. Current HST was about 20cm at noon, in that slab.

As we transitioned to northerly terrain. The older NSF was less pronounced surprisingly, and buried deeper. Hand pits produced shears on the most recent old now interface. We mostly just avoided any windslabs and didn’t gather much for targeted observations to the problem in that area.

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Avalanches: Before dropping Snodgrass NE facing slope of 35-38º, ski cut produced a stubborn to run, 8″ storm slab, propagation to a 30 wide slab, running as a sluff. Harmless, but enough cohesion in slab and weak enough buried near surface facets to run.
Weather: Near whiteout at TH to start, with improving visibility and decreasing winds and snow early afternoon. Cold temps, dropping during the day. Winds 40mph on ridge lines, and honking up high.
Snowpack: WIND. biggest player yesterday. 8-10″ dense, creamy new snow with drifts 1-4 feet deep. Significant cornice development, cracking on steep windloaded features.

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Avalanches: Large cornices fall on Gothics west face.
Weather: Overcast, blustery and COLD temps in the low to mid 20*F. Moderate to strong winds from the N with strong gusts and blowing snow. Light snow fall started around 1030 and periods of S1 S2 by 1100.
Snowpack: Blustery winds striped from the east of loading the SE slopes and gullies as well a NW wind cross loading from the ridge topes at 11,000ft. New snow ranged from 3-12” where snow was transported, it is defiantly possible for deeper snow deposits in other areas. Pit results: elevation 10,700 HS 320cm F 4F 1F P at 255cm down storm slab with an interface of wind boars at 230cm MFcr with rounding graupel layer under it. ECTN12BRK No other instabilities where observed other than small cracking produced skis in the skin track.

Avalanches: D1 sensitive windslab’s triggered from cornice work EBM. 12″ deep, 80′ feet wide. Smaller and stiffer D.5 windslabs on mid-elevation UWW.
Weather: Cold! Warmest temps were this morning and dropped throughout the day. 0* at Ridge and 9* at Study plot. Blustery day, peak gust
Snowpack: Protected loaded terrain had upwards of 13″ new. Windslabs were primarily stubborn with the exception of specific terrain features in EBM. Ski pen was soft underfoot, occassionally feeling old tracks. UUWW Castle Valley was more blown out than loaded, frozen chicken heads were greatest hazard at this elevation and aspect. Snowpack stiffened throughout the day with strong winds and cold temps.

Avalanches: Skier triggered a D1 wind slab on a SE aspect NTL, about 12″ deep and 25 feet wide. Ran on yesterday’s crusty surface. SS-ASc-R1-D1-I
Weather: Blustery squalls. Strong W to NW winds, moderate snow transport at ridgetops. Cold temps. Overcast with periods of broken skies. S1 at times.
Snowpack: About 2″ of new snow. Drifts up to 12″ in wind-loaded features. The new snow fell on stout melt-freeze crusts on southerly aspects, and added to the building slab over the 2/17 near surface facets on northerly aspects. There was about 6″ of recent, soft snow over this facet layer in wind sheltered, northerly aspects, and not enough cohesion/slab to produce signs of instability in steep terrain. Cracking and small slabs observed at mid elevations in wind affected areas on this layer, up to 10″ deep or so. One pit on a wind-sheltered, northerly, mid-elevation slope produced an easy Q2, SP CT result on the 2/17 NSF about 6″ deep. There is a rain crust about 20″ deep that did not produce any fractures, and no obvious surface hoar layers found deeper in the pit.

Small wind slab triggered on a SE aspect NTL

Small wind slab triggered on a SE aspect NTL

Avalanches: Checked out a natural D2/R3 persistent slab avalanche on a NNW aspect BTL that occurred before the most recent snow this past weekend. The slide was about 300 feet wide and occurred on a 33 degree slope. It had impressive propagation, propagating around tree islands. The slab was 55 cm thick with 10-15 cm of new snow on top. The slab was 4f+ hardness and had a non planar melt freeze crust in the middle of it. CTH 23 BRK on small grained facets/DF’s beneath the melt freeze crust. No failure occurred on the avalanche’s weak layer. The weak layer was most likely surface hoar (1/19 interface) but in the location of the compression test it had either already collapsed or decomposed. There were remains of a significant warming event that caused large rollerballs/small wet loose avalanche activity to come down from the steeper terrain above the avalanche – it seemed possible that this warming event and subsequent wet loose avalanche activity triggered the persistent slab avalanche.
Weather: Warm with broken clouds and moderate winds. Light graupel at times.
Snowpack: See avalanche description. Height of snow was 200 cm.

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