Monday-Thursday 1/30-2/2

Issued: Mon, Jan 30, 2017 at 8AM

Expires: Thu, Feb 02, 2017

Ride with your eyes open. The snow will be fun, but don’t throw good travel practices to the wind.

Group up out of harm’s way with eyes on the one person at a time on steep slopes.

Above 2,500ft Moderate

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

MONDAY TUESDAY WEDNESDAY & THURSDAY

DANGER SCALE

STORM SNOW:
Elevation:
 Above 2500 feet elevation
Aspect: 
All
Terrain: 
Steeper than 35 degrees
Sensitivity: 
Stubborn
Distribution: 
Specific
Likelihood (Human Triggered): 
Possible
Size: 
Small – Large
Danger Trend:
 Decreasing 
Forecaster Confidence: 
Fair

PERSISTENT SLAB:
Elevation: 
Mostly above 2500 feet elevation
Aspect: 
All
Terrain: 
Steep rocky slopes where facets exist under old and between windslab, especially interior of Thompson Pass
Sensitivity: 
Stubborn
Distribution: 
Specific
Likelihood (Human Triggered): 
Unlikely
Size: 
Small – Large
Danger Trend:
 Decreasing with time
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

LIST OF AVALANCHE PROBLEMS <here>

SNOWPACK DISCUSSION: Sunday’s good visibility allowed for many people to get out and test the new snow. No reports of obvious signs of instability.

coastal-zone-iconMaritime (Coastal): The two feet of storm snow that fell Jan.24-28 is settling and bonding to old surfaces. The storm left cooler dry powder at the surface. Warmer temperatures mid-storm left the steeps plastered white, looking more like the maritime mountains we love.

intermountain-zone-iconInter-Mountain (Transitional):  

  • Near Thompson Pass the storm snow settled to about two feet with dry powder on top. Testing Sunday showed a rough break at the new snow/old snow interface. Southerly wind during the storm left soft windlips and fat pillows in places. Due to wind having stripped high features bare before this storm, there are still rocks shallowly buried in places. Average depth in the hollows and less winded areas at 3000′ is near four feet.

interior-zone-iconContinental (Interior):  

  • The storm delivered about a foot of new snow, now settling to 6 inches of light dry powder over a breakable, more dense layer. This lays over old layers of weaker faceted snow. While there appears to not be concentrated force, basal facets were collapsing Sunday with testing above MP 40. This uncertainty with the interior snowpack, leaves the slim possbility of human triggered avalanches in upper elevation rocky terrain.

Find more photos and observations at the bottom of the page. Sharing your observations creates an informed community that everyone benefits from at some point.

Recent Avalanche Activity

coastal-zone-iconMaritime (Coastal):

  • No new observations since the activity during the storm.

intermountain-zone-iconInter-Mountain (Transitional):  

  • No new observations. During the storm, some loose activity out of steeps.

interior-zone-iconContinental (Interior):  

  • No new observations. During the storm, a few small, loose slides in steep gullies.

 

Recent Weather

WEATHER FORECAST for NEXT 24 HRS at 3,000 ft:
Temperature Forecast (Min/Max *F):  5 / 25
Ridgetop Wind Forecast (direction/mph): S / 5-20
Snowfall (in):  1-3
WIND & TEMPERATURE
PAST 24 hours
Ferry Terminal Thompson Pass
Average Wind Speed (mph) / Direction   3 / NNE  15 / SE
Max Wind Gust (mph) / Direction  9 / NNE  25 / SE
Temperature Min / Max (*F)  23 / 28  5 / 17

Weather Forecast:    Becoming overcast producing 2-5 inches of snowfall by Tuesday evening. Skies clearing Wednesday for another beautiful weekend.

Additional Info & Media

SNOW HISTORY: Valdez 1/29 AM Thompson Pass 1/30 AM
24 Hour Snow / Water Equiv. trace” /0.13″ 0″ /0″
Storm Snow /Water Equiv. (1/24-28) 24.7” /2.5″ 38″ /2.7″
Current Snow Depth 42.9″ 42″
January Snow / Water Equiv. 72.5″ /5.7″ 92″ / 7.9″
Total Winter Snowfall / Water Equiv. 168.6″ / 15.6” 235″ / 23.3″
Snowload in Valdez ? lbs/sq. ft.

 

SNOWFALL for LAST 24 HRS at OTHER STATIONS:
Nicks Valley at 4200 ft (in): 0″
Upper Tsaina at 1750 ft (in): 0″
Sugarloaf at 550 ft (in): 0″
SNOW DEPTH & WATER SURVEY (1/3/2017) Depth Snow Water Equivalent
Milepost 2.5 Valdez  22.7″  4.7″
Milepost 18 27.9″ 5.9″
Milepost 29 Worthington Flats 44″ 9.9″
Milepost 37 Tsaina River bridge 33.8″ 5.6″
This survey is done the first week of each month.

Weather Quicklinks:

  • NWS forecast for Northeast Prince William Sound <here>
  • NOAA NWS spot forecast for Thompson Pass <here>
  • Thompson Pass RWIS weather station <here>
  • MP 30 Nicks (Happy) Valley weather station at 4200 feet <here> (scroll to Nicks Valley)
  • Valdez Glacier UAF weather station at 6600 feet <data here> <map here>
  • Further weather resources <here>

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 VAC Forecasts.
Pete Carter

Forecaster: Pete Carter