Avalanche Activity

On the twenty fifth day of April a human triggered avalanche took the life of a Beloved local Vadez heli ski guide.  Details are limited at this point.  Avalanche occurred at ~5800′ on a NW aspect in the Pencil glacier.  Skier triggered a storm slab near ridgeline which carried them over exposure.  Near surface facets at the new snow/old interface are the suspected weak layer.

4/26- A near miss occurred on Acapulco where 3 skiers were partially buried.  Details are limited, but indicate that the party caused a ridge line cornice failure causing them to  tumble down the west face.  Cornice fall produced a large avalanche that stepped down twice.

Snowslide Gulch produced a D3 wet slab avalanche that put debris on the highway and has temporarily dammed the river.  November facets are the suspected weak layer.

4/24- DOT reported a natural avalanche that covered Dayville road  for 50′ with up to 12′ of debris.  Slide originated at low elevation close to the road.

Snowslide Gulch produced significant wet loose debris that triggered wet slab avalanche activity.

4/12- Natural cornice fall was reported on Saphire that triggered a D2 deep slab on a north aspect at 6000 feet.
4/11-  Human triggered wind slab avalanches have been reported below ridgelines and on cross loaded terrain feature mid slope.  These have mostly been shallow with narrow propagations ( 4-8 inches deep and 15-30 feet wide).  Although there was a larger slide reported on 40.5 mile peak up to D2 with depths of 1-3 feet propagating ~150 feet. 

4/9-  Human triggered avalanches to size D2 have been reported failing at the 4/5 new/old interface up to 3 feet in depth.  Activity has been concentrated to northerly aspects in the mid elevation band. 

Photo of skier triggered D2 in a cross loaded gully on Python lowers, north aspect, ~3000′

4/7- Numerous natural storm slab avalanches were observed on every aspect below ridge lines and on steep rolls in the mid elevations.  All slides observed included the new snow with no step downs observed or reported.  Natural activity was more concentrated towards the continental forecast zone where faceting of the surface snow during the last clear cycle was more significant.

There were a couple remote triggered D1-2 avalanches reported on northerly aspects at mid and upper elevations as well as multiple human triggered slides.  Locations were not reported.

3/30-4/2- Cornice fall has been reported in isolated locations with significant loose snow entrainment or slab avalanches resulting.  

Witnessed a Natural D2 avalanche resulting from cornice fall on a north aspect of pt 6330 just SW of Elephant.  No slab observed, just significant entrainment.

3/26- Details are very limited at this time, but there was a near miss in Gully 1 on Saturday 3/26.  Two people were fully buried and one partially.  A group in close proximity witnessed the avalanche and was able to dig the party out without incident.

3/29- Natural D2 avalanches off south aspects of Three Pigs.  Some of these stepped down and produced slab avalanches.

Several D1-1.5 skier triggered avalanches were reported across the forecast area within the storm snow and wind slabs.

3/23- Skier triggered wind deposit reported in the Iguana Backs at ~4000′ on a NW aspect.  Slide didn’t go anywhere because it was initiated from terrain less than 30°. Deposit was 2.5 feet deep at the deepest spot and was reported as failing on buried surface hoar.

3/22-  Skier triggered D2 windslab avalanche  on a west aspect near schoolbus.

3/21- Numerous natural D1 windslab pockets reported releasing from W-N-E mid and low elevation convexities.

3/20- Natural D3 hard slab NE of Averys

3/18- Ski cuts have been reported as productive at the new/old interface from 3/15.  These have been small and in the 6-8 inches deep.

3/7-  More skier triggered avalanches, mostly D1-D2’s failing at the 3/3 BSH.  

A local snowmachiner that was traveling through Marshall Pass reported a very notable natural deep hard slab that failed at the November facets.  Avalanche occured on a North aspect between the Schwan and Woodworth glaciers failed at the ground and ran into the Tasnuna river valley. Avalanche was estimated as D3-D4 with a crown depth over 10 feet.  

Another deep hard slab released naturaly on a high south aspect ~5500′ behind Averys.  

3/6- Numerous skier triggered D1-D2 avalanches occured failing at the new snow/old snow interface on surface hoar buried 3/3.  Ski cuts were reported to be very productive with sensitivity ranging from touchy to very touchy.  Most of these avalanches occured further back from the road corridor.  Although, one notable skier triggers D2.5 occured on Cracked Ice on a north aspect at ~4000′ that appeared to be 1000 + feet wide.  D1 naturals occured on 40.5 mile.

3/5- Numerous D1-D2 natural avalanches occured within the storms now 1-2 feet deep.  These occured mostly on northern half of the compass.  Including Little and big oddesssey, Gully 1, Mt Dimond moraine and Iguana Backs.  A couple of slides were also noted on the southern half of the compass D2.5’s on Hippie ridge and Three Pigs.

2/28- Numerous wet loose running at low elevations with some reported gauging to the ground above town.

2/23-  Full depth hard slab avalanche in steep rocky terrain.  East facing side of RFS draining into Cascade Creek.

HS-N-R2-D2-O/G  Steep Camp Couloir 2

Rhinestone Cowboy- 

2/17-18-  A Significant avalanche cycle occurred during this time period.  Most of the activity failed on deep persistent weak layers.  These were the 1/24 facet-crust combo and the November facets.  Numerous hard slab avalanches were observed that failed near the ground.

Deep hard slab activity included: Billy Mitchell, Happiness, 40.5 Mile Peak, NE Crudbusters Multiple spots around the Tonsina Glacier, West side of Iguana backs (really wrong place), Multiple spots in the Tsaina valley, Girl Mountain, Cracked Ice, Python, Buttress west of Nicks (this is has slid multiple times this year), North Oddessey shoulder.  This is only a portion of the activity that occured.  

Most of the activity occured around 4000′, although there were outliers at upper elevations.

Billy Mitchell

Iguana Backs (Really Wrong Place)

Girls

Python

Cracked Ice

Tonsina Glacier

North Oddessey Shoulder

2/17 – Keystone Canyon was reported to have many size 1-2 loose avalanches on the steep canyon walls.  Crowns with depths of 10-15″ have been reported as well on the ice climbs Simple twist, Bridal Veil and Green Steps.  Photo approach to Simple Twist

2/15- A large deep persistent avalanche occurred on “Back It In” near Mt Dimond.  The trigger is unknown, but was most likely triggered remotely by a helicopter landing on a recon mission.  It appears that a cornice fall triggered a shallow slab over rocks which then stepped down creating a deep slab ~500 feet wide that entrained the entire snowpack.  Several other deep slabs failed sympathetically below.

2/13 – Meteorite ramp was reported to have released full path failing at the bedrock.

2/9 & 2/10- Numerous natural avalanches occurred during this time period.  

Mt tiekel (50 mile) and 38 mile ran naturally, with 38 mile depositing a small amount of debris on the road.  

 The entire Python Buttress failed naturally close to the ground with a crown line approximately 1/4 mile in length. Numerous avalanches in the gully to the east occured as well.  Debris from both areas extended ~200 meters across flat terrain.  

 Gully 2 and Nicks had significant slides run into their fans.

 Snowslide Gulch ran naturally and hit the road.  

DOT mitigation efforts produced activity at Three Pigs and Snowslide Gulch.

Natural activity was more extensive than noted.  Snowfall continued after the event refilling crowns and preventing a good look at the extent of natural activity.

1/30-Several natural persistent slab avalanches were observed in the intermountain and continental zone.  

• Remote snowmachine triggered avalanche on Little Girls/ SE aspect/~3500′.   Member of group reported that 2 members of a larger party were waiting on the lower angle ridges (bro bowl up route) below the slide pictured waiting for the rest of a larger group.  Rider 2 went to play on a small hill nearby when rider 1 felt a large collapse and the slides pictured came down.  The rest of the group gathered up and about 5 minutes after the remote trigger felt an earthshaking collapse that had alders swaying and group reported the feeling of dropping/settling a vertical foot.  A noise that was described as a bomb quickly followed.  The group left the area immediately and did not observe any further avalanche activity caused by the collapse.  Other collapses were noted later in the day.