AVALANCHES: 3 old persistent slab avalanches on North and East aspects above treeline, breaking below rock bands. D2 in size. Couldn’t see debris anymore, just crown remnants. Probably late December or early January slides.

WEATHER: Scattered clearing to few clouds by midday. Moderate west to northwest winds, probably gustier on ridgelines, with plumes off of high peaks.

SNOWPACK: Pole probing on north aspects near and below treeline felt mostly right-side up in the 4F to 1F range, with a slightly softer but not dramatic decrease in hardness near the ground. Near surface facets just below the new snow, which was only 2″ in this location. A few areas were trapdoor and fully faceted near treeline. We traveled over a good amount of terrain that likely hasn’t seen traffic and did not observe any signs of instability. Winds were scouring north aspects and forming sastrugi near treeline.

UPLOADS:

AVALANCHES: Windslab released after testing the top of cornice with my pole/ski. Propagated about 100 yards across and up to 3ft deep in places at the crown. Did not step down to release persistent slab

WEATHER: High winds blowing (40-50mph) from the W NW direction after 2-4 inches of wet snowfall on (1/31). Mostly sunny skies –

SNOWPACK:

UPLOADS:

Skier triggered windslab on east aspect 100 yards wide and up to 3ft deep in places at the crown.

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WEATHER: Partly sunny skies with strong winds. Winds were strong enough to cause tree tops to sway and to transport snow on open areas within Snodgrass. Appeared as if winds originated from the NE and shifted from NW. Blowing snow was visible on all peaks and ridges within Crested Butte Zone.

SNOWPACK: Snodgrass tracks on low angle terrain had been filled in.

UPLOADS:

AVALANCHES: On a SE aspect above treeline, we remotely triggered one soft slab from 20 feet away, 3-4″ deep, 30 feet wide. Harmless in size, ran on the the meltfreeze crust. SS-ASr-R1-D1-I. Otherwise, the new snow seemed fairly well bonded to the storm interface, with a few minor sluffs. One south facing basin near Twin Lakes had a significant wet slab cycle, looked to be from the early January warmup, with about 5 wet (ish?) slabs that ran naturally, D2’s in size.

WEATHER: Calm winds in the morning increased by late afternoon to moderate gusts, with snow transport beginning and some plumes off peaks. Overcast and very light snowfall (S-1) in the morning cleared to few clouds by sunset. Warm temps, cooling trend through the day. Felt like the Cascades in the morning.

SNOWPACK: 2-4″ of relatively dense new snow, no wind affect, sitting on the structures described below. Below treeline, the snowpack is entirely fist-hard facets, less than 36″ deep, boot pen to the ground. On southerly tilts, there is a surface melt-freeze crust and a few dacaying crusts in the upper snowpack with facet layers between. On B/N/ATL slopes, the thickest crust we observed was about 6″ thick on a steep, south facing incline, supportive to boot pen. Most crusts were supportive on skis but boots penetrated through.. On near and below treeline aspects where the crust is thin (<2″ thick, on lower angle terrain or more E, SE aspects), we observed widespread localized collapsing and cracking in this surface crust overlying facets, with about 5 rolling collapses that traveled across entire slopes. Wasn’t a concern with only a couple inches of snow above the crust at this point, but a big warning sign for things to come if we get a slab on top. Near and above treeline it was hard to find lingering persistent slab structure. All southerly slopes that we observed were just a stack of decaying crusts with facet layers between. East and northeast aspects N/ATL generally held thin snowpack that was all faceted, F to 4F or so, but specific windloaded features held very hard, relatively small slabs (pencil hard, 6-12″ thick) over facets, and we got 2 collapses on these types of slopes but no avalanches. We avoided a large bowl feature that appeared to have more significant loading through the winter season. It seems the PS here is isolated in location but still possible to trigger if you can find the slab, generally small in size, but could be large on some features.