Scarp Ridge

CB Avalanche Center2015-16 Observations

Location: Kebler Pass Area
Date of Observation: 01/16/2016
Name: Zach Guy
Subject: Scarp Ridge
Aspect: North East
Elevation: 12,000 ft

Avalanches: Most terrain obscured by poor vis, but saw one natural wind slab on a wind loaded NE aspect above treeline. ~2ft crown, mostly filled in already, failed earlier in this storm. SS-N-R1-D2-U. Very small wind slab failed again in same path today.
Weather: Moderate to strong SW winds with moderate snow transport. S-1. Broken to overcast skies
Snowpack: 15″ of storm snow, with drifts up to several feet thick.

1/16. Larger crown getting filled in, smaller crown above it. NE aspect above treeline.

1/16. Larger crown getting filled in, smaller crown above it. NE aspect above treeline.

Mountain Weather 1/16/2016

CB Avalanche CenterWeather

Date: 01/16/2016

Embedded shortwaves under strong northwest flow continue to bring unsettled weather to our mountains. We should see a short lull and some patchy sunshine today before the next disturbance arrives tonight into tomorrow. We’ll be on the southern edge of the system, and our favored northern and western mountains should pick up another decent shot of snow before a brief respite on Monday. Look for 4-8″ by the end of the weekend under continued moderate to strong alpine winds.

Schuylkill Ridge

CB Avalanche Center2015-16 Observations

Location: Paradise Divide Area
Date of Observation: 01/15/2016
Name: Zach Guy and Brian Lazar
Subject: Schuylkill Ridge
Aspect: North East, East
Elevation: 9,200-11,300

Avalanches: On a NE aspect NTL, we kicked a small cornice that triggered a loose snow avalanche gouging into old facet layers and ran 1,100 vertical feet. Given the gulley feature it ran through, the slide could have injured or buried someone. L-AC-R1-D1.5-O. No other avalanche activity observed.
Weather: Overcast decreased to broken skies. S-1 snowfall in the morning. Moderate SW ridgetop winds, with light snow transport. Plumes from NW winds observed on Mt. Emmons as we left the trailhead in the afternoon.
Snowpack: 5 cm of storm snow over a widespread near surface facet layer. Minimal wind affect below leeward ridgelines, with drifts 10-15 cm. New snow was noticeably more wind affected mid to lower on the slope from cross-loading down valley winds. Observed drifts up 25cm thick with cracking up to 10 feet on steep rollovers, but no avalanches. HS in old refilling avalanche paths was 50-80cm. More a like 120-150 in areas that didn’t avalanches, but there weren’t many paths in this area that didn’t run. Most of the terrain avalanched during Xmas cycle leaving only weak snow 50-80 cm and almost entirely facets, with 5cm of new snow on top. Just below ridgelines the drifts the suspected wind slabs avalanche problem was not there. Suspect there are stiffer wind-drifted slabs near Kebler that got more snow to move, and also up ATL where winds were stronger.

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NE aspect near treeline on Schuykill Ridge. The red oval indicates areas we thought we would find developing wind-drifted slabs, but there was little wind affect up near ridgeline.   Surprisingly more wind affect closer to valley floor from down valley crossloading.

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Looking into the narrow gulley where a Loose Dry avalanche plunnged 1200 feet. Schuylkill Ridge 1.15.16

 

Mountain Weather 1/15/2016

CB Avalanche CenterWeather

Date: 01/15/2016

Moist northwest to west flow with several embedded shortwaves will keep snowy weather in the forecast through the weekend. The first pulse left us with upwards of 8″ of low density fluff in favored locations, The next pulse is moving in this morning from the northwest, showing decent moisture and precipitation upstream. Winds will swing around to the northwest as this system drops 3-5″ of snow today, perhaps more in favored locations. Saturday brings a lull in the action before another shortwave arrives Saturday night with continued light snowfall.

Large natural on west side of Ruby Range

CB Avalanche Center2015-16 Observations

Location: Kebler Pass Area
Date of Observation: 01/14/2016
Name: Zach Guy
Subject: Large natural on west side of Ruby Range
Aspect: East, South West, West
Elevation: 10,000-11,800 ft

Avalanches: We came across a surprisingly fresh D2.5 debris pile on west side of Ruby Range. Start zone obscured by clouds. Appears to have failed in the past week because the 10″ that fell on 1/7 was not on top of the debris. Could see some flanks mid track that looked about 2 feet deep and gouged to ground. Start zone was either SW or W aspect above treeline. Speculating that it was a persistent slab triggered by either a small wind slab a few days ago or a small wet loose avalanche yesterday? Noteworthy because it is the only persistent slab we’ve seen fail in the past few weeks, and one of the only large naturals from that aspect observed during Xmess Cycle. We observed 4 fresh wet loose avalanches on S/SW aspects below treeline.
Weather: Light to moderate snow (S1-S2). Moderate WSW winds with moderate snow transport at ridgeline. Overcast. Cold temps.
Snowpack: 2″ of new snow by 2 p.m.
N/ATL East aspects: Snow depths ranged from 180 to 250 cm. No wind effect in recent snow (ski pen was shin deep), except some slightly stiffer snow at ridgeline. No signs of instability on steep terrain.
N/ATL West aspects: Variable snow depth and structure; difficult to generalize. Upper start zones were mostly shallow and faceted (<50cm), with some pockets up to 180 cm deep with variable hardness structures. No signs of instability.

Small wet loose below treeline
Debris looking up towards obscured start zone
Looking down at debris.  Broken tree limbs and several meters deep.

Mountain Weather 1/14/2015

CB Avalanche CenterWeather

Date: 01/14/2016

Our recent clear sky weather and calm winds are no more as three disturbances will move through our area heading into the weekend. The first disturbance moves in today, but there isn’t anything to impressive about it. Bet we’ll see a trace of snow in CB and maybe a couple inches in the favored areas west of town by Friday morning. The next in the series moves in on Friday, this storm has a more available moisture and better dynamics, but it will be passing through the area quickly. So the bursts of snowfall will be short lived. The next storm then comes in around Saturday night and we don’t have the details for this one yet. In general, we’ll see unsettled weather through the weekend with stronger winds and periods of increased snowfall.

Crested Butte Area

CB Avalanche Center2015-16 Observations

Location: Crested Butte Area
Date of Observation: 01/13/2016
Name: Donny
Subject: Crested Butte Area
Aspect: West, North West
Elevation: 9000’ to 11,800′

Avalanches:
Weather: High thin clouds, light north wind above 11,500’ and Africa Hot – 34ºF at 11,000’ at 1:00.
Snowpack: No signs of instabilities. No slab present on any part of tour – full depth facets with HS between 50cm and 80cm.

Emmons Structure

CB Avalanche Center2015-16 Observations

Location: Crested Butte Area
Date of Observation: 01/13/2016
Name: Evan Ross
Subject: Emmons Structure
Aspect: North, North East, South East
Elevation: 9,000 to 12,000

Avalanches:
Weather: Mostly clear with high thin clouds building by 11am. Calm wind. Very cold inversion already set up again while crossing the slate river at 3:30pm.
Snowpack: Near surface facets or weak surface snow is all over the place. Recent winds have buffed or stripped snow from north to west facing slopes near the summit ridge lines of Mt. Emmons.

Snowpack structure on a protected SE aspect, 32 degree slope at 11,200 was just crusts and facets for about 80cm without any slab or avalanche problem.

Snowpack structure in Redwell just after dropping into the bowl and where the slope becomes uniform below cliffs, NE aspect 35 degree slope at about 12,100, was a perfect and scary feeling persistent slab set up. HS 130, with an estimated 1f to 4F+ slab about 60cm thick over about 60cm of very weak feeling structure below. Still, many tracks on slope with no result. If that same structure exists on the steeper slopes in the area where there are no tracks, then they seem like they could still produce a persistent slab avalanche. Only had a chance to sample this one small area in this large terrain feature.

Snowpack structure in the north facing runout of redwell below 10,600ft was a simple weak, faceted snowpack with little layering remaining.

Mountain Weather 1/13/2016

CB Avalanche CenterWeather

Date: 01/13/2016

Cold valley inversions will once again warm throughout the day with one last sunny day this week. A series of three short waves will then move through our area over the remainder of the week. The first will start arriving tonight with increased clouds and a couple inches of snow tomorrow. We should see better snow accumulation out of the next shortwave passing Thursday night into Friday. This system has better moisture but will move through the area quickly, so snow showers will be shorter lived. Then we’ll see another shortwave moving through around Saturday night. These are just small storms, but combined together they should keep conditions fresh this weekend.

Crested Butte Area

CB Avalanche Center2015-16 Observations

Location: Crested Butte Area
Date of Observation: 01/11/2016
Name: Donny
Subject: Crested Butte Area
Aspect: North East, East
Elevation: 11,200

Avalanches:
Weather:
Snowpack: 32º slope, ENE Aspect @ 11,200’ near Gothic. SkiPen: 15cm; BootPen: 50cm; HS 115; 0-10cm sintered DH; 10-30cm F+ Facets; 30-100cm SLAB, 1F at bottom, 4F at top; 1cm of sun crust; top 15cm recent storm snow, fist hard. ECTP (15) (x3) failing within facets about 25cm from ground. The slab popped right out.

We skied the slope and didn’t observe any signs of instabilities.

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