Mountain Weather 3/9/2017

CB Avalanche CenterWeather

Date: 03/09/2017

Another warm, spring day is on tap today with temperatures at 11,000 feet and above climbing into the mid to upper 30s today and tomorrow. We will see an increase of westerly wind increase midday, especially near ridge top, before decreasing toward sunset. Tomorrow looks even warmer, before temperatures moderate slightly. Next chance of significant precipitation is 7-10 days away.

Mount Emmons

CB Avalanche Center2016-17 Observations

Location: Crested Butte Area
Date of Observation: 03/08/2017
Name: Steve Banks
Subject: Mount Emmons
Aspect: North East, East, South East, South
Elevation: 9000-11400

Avalanches:
Weather: hot again…sorta. Warm on the South facing skin track with light breeze until 11,000. Temps in the upper 20’s with strong solar under clear skis. Above 11,000 there was a strong N wind blowing up to 50 MPH at 12,000.
Snowpack: 2 cms of new snow from surprise snow squall last night over semi-supportive wind and sun crust. Posed some gloppy skin issues going from sun to shade in the trees. Above TL the new snow added to previous wind loaded slopes, but isolated to right at/below ridge line. All aspects from N-NE-E-SE where open and less treed looked blown out, wind jacked with raised tracks in area viewed. Below new wind load (hundred feet below ridge line) quickly transitioned to wind buff, slightly breakable almost but not quite chalky. Lots of sustrugi everywhere.

Skinning up a more sheltered South facing slope at 11,000 the new skiff was moist and sun crust below was wet. Wetness did not go below the old 4 cm thick crust.

Steep N facing below treeline maintained dry snow, and faceting was evident. Some areas even felt a bit “trap door” and punchy, but this was not consistent.

Snodgrass

CB Avalanche Center2016-17 Observations

Location: Crested Butte Area
Date of Observation: 03/08/2017
Name: Will Nunez
Subject: Snodgrass
Aspect: North East
Elevation: 9400-11100

Avalanches: Small D1 wet loose on the east face of gothic, small sluffing on N-NE aspects.
Weather: Clear and HOT with a light breeze out of the NW
Snowpack: The persistent slab structure was found on N-NE terrain at 10,500ft. A quick pit reveled hand hardness of F20cm 4F30cm 1F30cm HS230cm. A 1.5mm faceted interface 40cm down was tested by a compression test resulting in CTH22Q2. Another layer of concern was found 90cm down while doing a shovel sheer. It had lots of resistance but came out as planer with 2mm rounding facets. N-NE faces stayed dry while E faces warmed up and started to crust up around 3:30pm, Surface Hoar was present in protected slopes and shaded terrain. No other instability’s were observed.

Coneys Avalanche

CB Avalanche Center2016-17 Observations

Location: Crested Butte Area
Date of Observation: 03/08/2017
Name: Ian McConnell
Subject: Coneys Avalanche
Aspect: North, North East
Elevation: 10200′

Avalanches: observed natural slide ~1-2 days old; NE aspect; 10500′; D1, R1; crown roughly 150′, running 200m

triggered after rollover about 2/3rds down coneys right. 10200′, D1.5, R1.5, AS, windslab broke on near surface facets; 20′ deep 100′ wide crown, running 100m, 35-36 degree slope
Weather: Clear; moderate winds out of the NW; temps around 3 degrees C
Snowpack: snowpit on similar aspect and elevation yielded CTM (7, SP), breaking on buried SH interface. HS observed at 260cm
Coneys ridgeline heavily wind affected; observed sastrugi and loading throughout N-NE aspects.

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Teocalli, Pearl Pass, Tagert Hut Area

CB Avalanche Center2016-17 Observations

Location: Brush Creek Area
Date of Observation: 03/08/2017
Name: Evan Ross
Subject: Teocalli, Pearl Pass, Tagert Hut Area
Aspect: North East, East, South West
Elevation: 10,000-13,000

Avalanches:
Weather: Mostly clear. Generally calm to light winds, with some very strong westerly gusts at Ridgeline.
Snowpack: South and west facing slopes were mostly blown back to old snow surfaces with plenty of wind jack. Easterly and Northerly slopes were either very wind effected, wind pressed, or wind loaded by the last extreme wind event. Snow surfaces on these aspects depended on the sounding topography and how the winds had come through the area.

The most concerning structure we looked at was on a northeasterly slope at 12,500ft with wind deposited and pressed snow over 4f to 4f- near surface .facets. Lots of variability in the new or old snow surfaces. Avoided a few wind loaded terrain features, otherwise no other obvious signs to instability noted.

Snow quality was better on the Crested Butte side of the Elks then the Aspen side:}

Teocalli

CB Avalanche Center2016-17 Observations

Location: Brush Creek Area
Date of Observation: 03/08/2017
Name: Zach Guy
Subject: Teocalli
Aspect: South, South West, West, North West
Elevation: 10000-13200 ft

Avalanches: No signs of instability except some very minor rollerballs at lower elevations, not enough fresh snow to start wet loose avalanches.
Weather: Few clouds. Light to moderate winds at ridgetop.
Snowpack: 1-2″ of dense, wind-affected recent snow over old crusts, windboard, etc. We found a couple of isolated drifts up to 12″ thick, but otherwise not much for recent windloading.

Whetstone and Mt. Emmons obs

CB Avalanche Center2016-17 Observations

Location: Crested Butte Area
Date of Observation: 03/07/2017
Name: Zach Guy, Evan Ross
Subject: Whetstone and Mt. Emmons obs
Aspect: North East, East, South East
Elevation: 9000-11,600

Avalanches: No signs of instability near or below treeline.
Weather: Decreasing winds through the day. Few clouds.
Snowpack: A few inches of new snow. Traveled in gullies, leeward ridgelines, and other suspect features for wind loading N/BTL and drifts were negligible; less than 3″ deep. It appears the extreme winds blew more snow away than loaded it. In areas where we did encounter thin drifts, it was easy to produce cracking, indicating poor bonding.
Investigated the PS structure NTL. On SE aspects, there was a ~3cm crust capping a faceting slab (~30 cm) over the crust facet layer, and this structure appeared to be non-concerning where we traveled. On an E aspect, several crust/facet layers were buried 40 cm deep, and produced non-propagating, broken fractures under hard initiation (ECTN 25 BRK).

Smith Hill

CB Avalanche Center2016-17 Observations

Location: Crested Butte Area
Date of Observation: 03/08/2017
Name: El Duderino
Subject: Smith Hill
Aspect: East, South East, South West, West
Elevation: 8,900-9,800

Avalanches: none observed
Weather: cold & moderate wind in AM gave way to mild & calm in PM
Snowpack: 2 small collapses at ridgeline on Easterly wind loaded ~20* slope

Mountain Weather

CB Avalanche CenterWeather

Date: 03/08/2017

Our weather will continue its transition towards clear, calm and warm as weak high pressure develops over the West. We’ll see temperatures rise to freezing today and reach towards 40F tomorrow under mostly clear skies and fairly tame winds. Enjoy the sunny weather — the storm track looks to stay north of us through the next week. .

Stormy BC Ski Day

CB Avalanche Center2016-17 Observations

Location: Crested Butte Area
Date of Observation: 03/06/2017
Name: Jake
Subject: Stormy BC Ski Day
Aspect: North East, East
Elevation:

Avalanches:
Weather: Indeed. OVC to Obscured back to OVC. Moderate to Strong Winds from the North at valley floor all day, WSW at ridge top, somewhat calm in the trees. S1-S3 rimed PP and grauple (sp?) throughout day with a lull at 1630. Full conditions, prime day for an extra buff and a double check on client clothing.
Snowpack: 1 big whumpf in the valley just before starting our ascent, no other signs of instability. Similar results to Dave with a quick pit just off the ridge on skier’s Right of the bowl- CT 16 45cms down on crust. Sorry I didn’t get a better description of the break, little blustery but if we want to go old school I’d say Q1.25 to be precise. Broke clean but didn’t pop. No signs of instability on the ski, kept it low angle. Certain wind transport all day.