Avalanche Activity

4/18: Numerous moderate to very large wet loose and wet slab avalanches were seen and reported on south aspects from sea level up to 6000′.

4/17: Full depth wet slab avalanches were observed on south faces of  Town Mountain, Hogsback and Hippie Ridge.

4/16: Widespread wet loose avalanches observed in the Port of Valdez up to 5000′ on east through west aspects.

 A soft slab avalanche was observed on Hogsback that initiated from a rockband at ~4500′, west aspect, ~500′ wide.  Looked to be about 2-3′ deep, but was observed through binoculars so that is just a guess.  Avalanche may have been snowmachine triggered as there were tracks directly adjacent to the avalanche, but that is unconfirmed.

4/14: Observed numerous small to moderate wet loose slides off solar aspects up to 4000′.

4/6: Small to moderate dry loose “sluffs” were observed on east through northwest aspects above 3000′ in terrain steeper than 40°.  Did not observe any soft slab avalanches triggered by dry loose slides.  

3/26: Small natural wet slab avalanche that originated from a point release was observed at MP 40 on a south aspect.  100′ wide, originating from ~2000′, ran to ground.

3/22: Small snowboard triggered wind slab avalanche reported in skate park.  ~3000′, southeast aspect, 1 foot deep, ~40′ wide.  SS-ARu-R1-D1.5-I.  Other small natural releases were reported in the area as well.

3/14: Numerous D1 wet loose avalanches observed 3/14 on south aspects in steep terrain. 

• Glide crack release on the north side of slater creek “east peak zone”, south aspect ~3500′.

3/11: 2 Human triggered avalanches observed on the Thompson Pass corridor.

• Snowmachine triggered avalanche directly above the Thompson Pass airstrip.  Released from a thin section of windslab which then stepped down and released the entire snowpack on an unsupported slope. Crown was about 10 feet deep.  HS-AMu-D2-G

    Skier triggered avalanche in Nicks Happy Valley.  Skier was traversing the wind loaded northwest aspect of the gully and released a slab ~1 foot deep and 100′ wide, ran ~150 vertical feet to the bottom of the gully. SS-ASu-D1.5-I.

3/5: -Natural D 2.5 occurred on the NW aspect shoulder of the Python Buttress “Ptarmigan Drop” milepost 31.  Avalanche crown was reported to be 10-15 feet deep by DOT and ran to the ground.  Crown was quickly filled back in by intense snow transport.

• Natural D3 occurred directly across from the Tsaina lodge on a south aspect of Hippie Ridge.  Originated at 4000′, ~1500′ wide, stepped down twice and ran to the ground .

• Natural D2 on south aspect of Hippie Ridge 1 mile north of previously mentioned avalanche. 4500′ created 2 sympathetic avalanches on either side at 4000′

• Natural D3 on the south face of South Tiekel. Originated from 3 smaller slides at ~5700′ and stepped down multiple times and eventually ran to the ground.  Initial step-down propagated an avalanche 2-3000′ wide. Ran full path.  There were reports that sympathetic avalanches were associated with this avalanche over a mile away.  Photo from over 2 miles away. 

3/4: A natural D3 avalanche ran above the 37 mile tsaina bridge.  South aspect ~5500′, stepped down multiple times,  ran to the ground in places.   The main debris fell short of the highway, mature uprooted trees 6-12 inches in diameter were thrown onto the road by powder blast.

-The gully downstream of Bridal Veil Falls produced a large avalanche, D2.5, that buried the river with over 10′ of debris,  the powder blast pushed sticks into the parking lot on the other side of the road.

3/3: DOT mitigation work produced another large avalanche that affected the Richardson Highway at ~ mile 39.  Initial reports stated that the avalanche buried the highway under 15 feet of debris for ~500 feet. 

2/28: Natural wind slab avalanche 4000′. N-HS-R2-D2, West aspect slope that descends from Crudbuster basin into IguanaBacks. Stepped down immediately below initial crown, to the ground in places.

2/26: Large natural observed at 48 mile off Point 5064 (Stuart). N-HS-R3-D3, N-W aspects. Observed from the highway. Looked fresh, probably within the last 24 hours. Appears to have released from a N aspect bowl ~40-45° at~4500′, then stepped down and wrapped around the corner onto NW-W aspects. Crown on step down is estimated to be over 3 meters deep in places. Couldn’t see extent of track length. Crown was over 1/2 mile wide. 3 small, sympathetic pockets were observed over 1/2 mile away in moderate terrain with crowns ~1-2 meters. Picture taken from over 3 miles away.

2/24: Natural avalanche observed on the north face of Goodwills’ ~5500′, D-2.5, 200-300′ wide. Ran to the bottom of the slope ~600′, crown ~5′ deep. 

2/23: – Natural avalanches D2-2.5 on the east face of Mt. Tiekel were observed.

• At the headwaters of Quartz Creek, MP 54, a large group of snowmachiners potentially remotely triggered a D2 avalanche.  See observations page.

2/21: Multiple natural and human triggered avalanches were observed 2/21.

• A natural avalanche hit the road near 39 mile.  This natural originated from mid-slope elevations and put a small amount of debris onto the road.  DOT mitigation efforts produced a D 3.5 avalanche that originated from the upper mountain ~6000′ and stepped down multiple times.  Crown depths were reported as significant.  Debris 6-15 feet deep buried 1000′ of the Richardson Highway. 

 

Debris along the highway after DOT cleanup work.

Debris that over ran the highway and was deposited into the Tsaina Gorge.

• A natural released at the toe of Worthington Glacier on a slope just south of the toe on a north east aspect.  Crown was over 400′ wide and crown depth averaged 3-5 feet and stepped down to over 10′ deep at one point. There was a small sympathetic associated as well.
• A small deep pocket (50′ across ~4′ deep) was observed on the east side of the highway below Gully 1 that was remotely triggered by snowmachines high marking above.
• Two small avalanches released off a south slope above the airstrip with unknown trigger.  Many snowmachine tracks were present in the area around the slides.

Natural near the toe of the Worthington Glacier.

2/20: Two side by side avalanches were observed on the NW shoulder of the Python buttress ~3500′. Crown 2-300′ across and ~3’+ deep. These slides ran into the flat ~800 vertical feet.  Slides were triggered by DOT mitigation work 2/19.

2/20: 2 paths on Three Pigs at MP 42 slid naturally to the middle to lower portion of their aprons, D2.5.  Low clouds prevented ability to see what elevation they originated from.

2/20: A natural avalanche was reported on the north shoulder of Mt Tiekel at ~4500′.  Details were limited but the entire slope avalanched and crown was reported to be 2 meters deep. R5-D2.5~.

2/19: A natural avalanche at 32 mile buried the Richardson Highway under 10 feet of snow for ~100′.  This caused the highway to close for the majority of the day.  This slide released from the lower bench of RFS on a north aspect.

2/14: Dry loose D1-2 natural avalanches were observed running over the Wowie Zowie ice climb in Mineral Creek.

2/13: Natural and human triggered D1 avalanches were observed in Keystone Canyon.

2/12: A D3 avalanche at MP 38 hit the Richardson Highway and closed the road.  Released on a south aspect in the upper elevation start zones, ~5500′, and stepped down around 4-4500′.  Further DOT mitigation efforts on Three Pigs and 40.5 Mile produced no results.