Tuesday-Friday 4/4-4/7

Issued: Tue, Apr 04, 2017 at 8AM

Expires: Fri, Apr 07, 2017

 

Friday April 14 bon fire: VAC Full Moon FUNraiser with Acoustic Avalanche @  Tsaina Lodge

Above 2,500ft Considerable

1,800 to 2,500ft Low

Below 1,800ft Low

Degrees of Avalanche Danger ?

1. Low
2. Moderate
3. Considerable
4. High
5. Extreme

Avalanche Danger Rose ?

Avalanche Problems ?

Problem Details

TUESDAY WEDNESDAY THURSDAY & FRIDAY

DANGER SCALE

 

STORM WINDSLAB:
Elevation:   Above 2500′ elevation
Aspect:   Primarily north though west
Terrain:   Steeper unsupported slopes
Sensitivity:   Stubborn
Distribution:  Isolated
Likelihood (Human Triggered):   Possible
Size: Small – Large
Danger Trend:  Decreasing
Forecaster Confidence:  Poor

PERSISTENT SLAB:
Elevation:
  Above 2500′ elevation
Aspect:
    more likely on northerly aspects
Terrain:    
unsupported steep slopes with thin coverage
Sensitivity:
  Stubborn
Distribution:
  Isolated where windslab exists over facets/depth hoar
Likelihood (Human Triggered):
   Possible
Size:
  Small – Large
Danger Trend:
   Steady
Forecaster Confidence:
  Poor

AVALANCHE PROBLEM SCALE DESCRIPTORS:

Sensitivity: Non-reactive, Stubborn, Responsive, Touchy
Distribution: Isolated, Specific, Widespread
Likelihood: Unlikely, Possible, Likely, Nearly Certain
Size: Small, Large, Very Large (size scale <here>)
Danger Trend: Increasing, Steady, Decreasing
Forecaster Confidence: Good, Fair, Poor

AVALANCHE PROBLEM TOOLBOX <here>

SNOWPACK DISCUSSION:

Continental (Interior) Specific:  

The upper elevations exposed to wind wind slabs with isolated areas sitting over sugar snow. North of Thompson Pass has less new snow to drift into widslab.

The concern is not knowing where a human could trigger a windslab that steps down to buried sugar snow releasing a persistent slab.

Find more photos and observations at the bottom of the page. Sharing your observations creates an informed community.

Recent Avalanche Activity

Continental (Interior) Specific: 

  • March 31: skier triggered size D2 avalanche at 3500′ North aspect. 40-60cm storm slab failed on buried near surface facets with a old windslab as the bed surface. A possible sympathetic released lower on the same slope, with a crown depth 60-100cm, harder slab.
  •  March 25: reports of upper elevation (>4500′ elevation) human triggered windslab to size D1.5 to a foot thick releasing off steep slopes, mostly in the Maritime to Intermountain areas
  • March 24: report of significant collapses, as large as whole basins whumphing, in areas on the northerly and easterly outreaches of our Inter-mountain zone, and into the Continental zone.

Recent Weather

See Maritime Zone for updated weather.

Additional Info & Media

Weather Quicklinks:

SNOW CLIMATE ZONES:

  • coastal-zone-iconMaritime (Coastal) – from the Port of Valdez to Thompson Pass, all waters flowing into Valdez Arm and everything south of Marshall Pass.
  • intermountain-zone-iconInter-mountain (Transitional) – between Thompson Pass and Rendezvous Lodge.
  • interior-zone-iconContinental (Interior) – the dry north side of the Chugach (north of 46 Mile, including the Tonsina River).

Photo of Thompson Pass

thompson-pass-ski-runs

Interactive Map of Valdez Forecast Areas w/ Many Resource Layers (Trevor Grams)

climate-zones-topoclimate-zones-satellitegoogle-earth1

Run Map of Thompson Pass Area (Sean Wisner) (2MB download)
VAC Run Map Thompson Pass

NEWS: Our region is “one of the snowiest places on earth” – Serendipity / Rendezvous snowfall record set in 1963 <here>.

Free smart phone avalanche forecasts at: http://www.avalancheforecasts.com/

Posted in Continental Forecasts.
Pete Carter

Forecaster: Pete Carter