Tuesday-Friday 4/11-4/14

Issued: Tue, Apr 11, 2017 at 8AM

Expires: Fri, Apr 14, 2017

Warming afternoon temperatures will increase the chances of triggering a slide. Always carry your avalanche rescue gear, use terrain to your advantage, and always ski/highmark one at a time with the rest of your group out of the runout zone.

Friday April 14: VAC Full Moon Spring Fling FUNraiser with Acoustic Avalanche at the Tsaina Lodge

Above 2,500ft Moderate

1,800 to 2,500ft Moderate

Below 1,800ft Moderate

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

WET AVALANCHES:
Elevation:
   Below 5000′
Aspect:
 South, East in AM, West in PM
Terrain:
Steep terrain near rocks and vegetation.
Sensitivity:
   Touchy when warmed.
Distribution:
   Specific.
Likelihood (Human Triggered):
   Possible
Size:
  Small-Large
Danger Trend:
   Increasing quickly each day with warming temperatures, falling at night
Forecaster Confidence:
   Good

PERSISTENT SLAB:
Elevation:
  Above 2500′
Aspect:
 All
Terrain:
Slopes > 35*
Sensitivity:
   Stubborn on northerlies, Touchy when warmed by sun
Distribution:
   Widespread
Likelihood (Human Triggered):
   Possible
Size:
  Small – Large
Danger Trend:
   Decreasing
Forecaster Confidence:
   Fair

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:

intermountain-zone-iconInter-Mountain (Transitional) Specific:  

The most recent storm produced 2-3 feet of new snow in the inter-mountain region surrounding Thompson Pass. The new snow has settled to around 1 foot of medium density powder in areas that haven’t been baked away by the sun. One must travel to elevations around 5000~ feet to find soft powder snow.

There have been reports of the afternoon sun triggering natural avalanches. The first type being wet avalanches which have the potential to slide to the ground. They are most likely to be triggered on southerly aspects especially in elevations below 5000′ when temperatures reach above 32 degrees. The second type being dry slab avalanches consisting of the most recent snowfall. These avalanches are possible on all aspects other than south, realistically anywhere dry powder snow can be found. The warmer temperatures in the afternoon will certainly increase the chances of triggering a slide. 

Sharing your observations creates an informed community.

Recent Avalanche Activity

intermountain-zone-iconInter-Mountain (Transitional) Specific:  

  • April 9: new natural slab avalanches on the WSW face of Sapphire and west aspect in the Books.

    April 9 Avalanche in motion on west face in the Books. Photo: Bobby Lieberman

    April 9 WSW face of Sapphire. Fresh natural slab avalanche. Photo: Steve Schumm

     

     

     

 

  • April 6-8 Large wet debris running far into flats on south side of Tone’s Temple.

    April 6-8 Wet loose triggered slabs off of southerlies along Worthington Glacier.

    April 6-8 Sun triggered loose slides off Girls Mountain south face.

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 Intermountain Forecasts.
Kyle Sobek

Forecaster: Kyle Sobek