Valdez Avalanche Activity

4/9- Skier triggered D2 avalanche reported on a wind loaded NW aspect of Berlin Wall ~5400'.  Skier was caught and carried, but not buried/ no injuries.

Small wind loaded pockets D1-1.5 were observed to be sensitive to human triggers in cross loaded terrain on Billy Mitchell.

4/7- Numerous D1-1.5 natural dry loose avalanches observed that occurred mid storm 4/5-6.  No step downs observed.  

Several small (D1) human triggered avalanches were observed along the road corridor where the new snow had been wind affected.

4/6- Skier triggered D1 reported in Gully 1 on a wind loaded convexity.  

4/2- D1.5 skier triggered wind slab avalanche.  NW aspect/~4000'.

4/1- Multiple skier triggered D1 avalanches were reported on a variety of aspects.  These were wind slabs in the 4-8 inch range. 

3/31- Skier triggered avalanche reported at high elevation of the Maritime climate zone.  This failed on surface hoar that was buried on 3/30.  No skier involvement. Crown depth was 4-8 inches.

3/24-  Ski cuts were reported as being productive, with avalanches up to D2 at the 3/21 interface.

 

3/18-21- Several D1-D2 human triggered avalanches have been reported.  For the most part these have been outside our forecast zone and appear to be more likely in areas with either a weaker underlying snowpack (continental zone) or where storm totals were higher (SE of Thompson Pass).  Remote triggers have also been reported as the Hamilton storm slab has settled and gained cohesion.

 

3/17- Multiple D1-D2 natural storm slab avalanches were reported and observed along the road corridor.  These all failed within the storm snow with the exception of one deep persistent avalanche reported on Billy Mitchell.

3/8- Numerous wet loose D1's on solar aspects with some D2 step down slab avalanches being reported and observed.

 

3/4-  Lower Girls- SSE ~ 4200' HS-N-D2

Nicks Buttress- N ~ 4000'  SS-N-D2.   Both of these were wind loaded slopes, with the Nicks Buttress slide involving a cross loaded gully.

 

3/3-Natural D2 wind slab avalanche that likely failed on persistent weak layer judging by the length of propagation.  2/23 BSH is the suspected weak layer.  Hippy Ridge/ South/ ~3800'

 

2/24- Natural D2.5 wind slab avalanche that failed on 2/23 BSH in the Tsaina Valley / S-SE aspect ~6000'/ ran ~3500 vertical (full track)/ crown ~1 foot deep and ~2000' wide. SS-N-R4-D2.5

2/22- Natural D 2.5 cornice fall avalanche was reported on a NW aspect/ ~6000 in the books.

 

 

 

2/20- Numerous D1-D2 natural and human triggered avalanches were observed and reported up to 1 foot in depth on a variety of aspects.  These occurred in areas where fresh wind slabs were present.

- D3 natural avalanche observed on Snoopys (Port of Valdez). NW aspect/ ~5000'/ ran ~3500 vertical feet with a track length of approximately 1 mile mapped on Google Earth.  This was a hard slab avalanche the failed at weak layer in the mid snowpack. HS-N-R4 D3.  No other avalanches of this size have been observed or reported in our forecast area.

 

 

 

2/15- The sun came out in full force after 6 inches of new snow and produced a significant amount of point release wet/loose activity near the coast on solar aspects.  2- D2's were also noted in the mid and high  elevation band of town mountain and Mile high.

 

 

2/9- Several small (D1) natural avalanches were observed that failed on steep wind loaded terrain.

2/7- DOT avalanche control work on 2/7 produced several D2-2.5 avalanches. All of these appear to have failed at the new snow/old interface without any step downs observed.  Avalanche activity mostly occurred in the mid elevation band 3500'-4000' on the Buttresses of RFS, Cracked Ice, and Python.  The most significant results occurred on Berlin Wall at ~5000' with a crown that looks to exceed 2 meters.  This was likely due to significant wind loading during the storm.

Very little natural avalanche activity was observed.

1/26-  A significant amount of avalanche activity occurred during the 1/23-25 storm.  Avalanches were concentrated in the Intermountain and Continental zone and occurred on all aspects above 2000'.  Most of the activity appears to have failed mid storm at the 1/14 buried surface hoar layer (see problem 1) with crowns filled back in.  Notable avalanches occurred on: Crudbusters, Iguana Backs, Nicks Buttress, Gully 2 buttress, Little Girls, Easter Bunny, Averys, RFS.

Crudbusters north aspect ~4500' SS-N-R2-D2.5

Hippie Ridge south aspect ~4000' -SS-Ny-R1-D2

Giovanni (Buttress east of Nicks Happy Valley)north aspect ~3600' SS-N-R3-D3.  Stepped down to facets near the ground at ~3100'.  This was the only avalanche reported or observed with a step down to deeper weak layers.

Buttress between Nick and Gully 2. north-northwest aspect ~3500' SS-N-R4-D2.5

 

 

 

1/21- Several D2 natural avalanches were observed on wind loaded slopes that failed at the 1/14 BSH interface.  These probably occurred on 1/19. Avalanches were observed on Hippie Ridge South aspect, RFS Northwest aspect, Cracked Ice  Northwest aspect and Python (Cherry couloir) East aspect.  These all appeared to be 1-2 feet deep.

 

1/20- Numerous large (D2) wet loose avalanches released from steep planar slopes in the Port of Valdez.  These were caused by a foot or more of snow falling with temperatures rising to 40° F at sea level directly following.  No step downs noted.

 

1/17- Numerous wet loose point release were observed on solar aspects in the Port of Valdez.  Most of these originated from rocks were the suns energy permeated into dry snow and caused surface snow to become upside down.  No step down slab avalanches were observed.

 

 

1/13- Numerous natural shallow (D1) soft slab avalanches were observed on all aspects and elevations.  These were about 4 inches deep and look to have occurred during peak intensity of the 1/11 snowfall event.

 

 

1/7- Deep hard slab avalanche release between Catchers Mitt and Loveland Basin, ~3500'/SW aspect/ crown depth 1-6 feet. HS-N-R2-D2.

Crown Profile:

 

1/1- The New Years storm deposited 1-2 feet of new snow at valley locations north of Thompson Pass with rain falling below 2000' on the south side of the pass.  Very little natural avalanche activity was reported or observed above freezing line for the New Years storm. A crown on the north face of Tones Temple and SW face of Acapulco were noted.  These occurred mid storm within the new snow and were mostly filled in.   No deep slab release were observed.  Wet loose activity occurred below 2000' south of Thompson Pass with one large wet loose observed in Keystone Canyon.

 

12/15- DOT avalanche control work produced several D2-2.5 avalanches from upper elevations of Hogsback and South Three Pigs.  Step downs were noted with one slide suspected of failing at the ground. 

Natural D2-2.5 avalanche activity was observed on Python Buttress north aspect, Berlin Wall northeast aspect, Averys southwest aspect and Girls mountain just above Worthington glacier southwest aspect picture below.  There was also a significant amount of avalanche activity in Keystone canyon (Bridal Veil photo below) with at least 1 deep crown reported on the ice climb Gunnison.  Most of the avalanches observed involved only storm snow with only a few step downs observed.  Exceptions to this include DOT control work and the keystone canyon slide noted above.

 

 

 

Hard slab avalanche debris from lower Catchers Mitt. SW aspect, ~100 meters wide, ran 400 vertical feet.

12/12- Observation of natural activity was prevented by clouds and continuing snowfall on Thompson Pass and Valdez.

12/9- Several D2 natural wind slab avalanches were observed on S-W aspects at mid elevation in the intermountain region.  Crowns appeared to be 1-3 feet deep.    Catchers Mitt and Gully 1 were among the spots affected.

 

12/1-  2 D2.5 natural avalanches were noted on Three Pigs (Beaver slide, Pig Leg). Pig leg ran into the top 1/3 of the fan and Beaver Slide stopped near the end of its track.  These both likely occurred during the outflow wind event 11/26-11/29.

D2 natural wind slab was observed on 40.5 mile peak on a west aspect ~3000'.  Crown depth range estimated 1-2 feet and 200' long

11/14-  Debris from a D3 natural avalanche at snow slide gulch ended 100 vertical feet above the Lowe river.  

Large avalanches (D2-2.5)also occurred in multiple other locations including Berlin Wall, Catchers Mitt, South Three Pigs and Billy Mitchell.  The activity extends beyond this list, and mostly occurred during the peak of warming and precipitation on 11/13.

Multiple natural D1-1.5 avalanches were observed on multiple aspects at low elevation.  No step downs noted.