Arctic Man Avalanche Advisory

Issued: Sun, Apr 15, 2018 at 8AM

Expires: Mon, Apr 16, 2018

Avalanche Danger is Low in the Morning and High in the Afternoon

Thanks for checking the Arctic Man 2018 Avalanche Forecast. See you next year!

Above 4,000ft None

3,000 to 4,000ft None

Below 3,000ft None

Degrees of Avalanche Danger ?

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

Avalanche Danger Rose ?

Avalanche Problems ?

Problem Details

Wet Avalanches:
Elevation:   Below 4000′
Aspect:   SE – S – SW
Terrain:   Southerly facing terrain >25 degrees exposed to sun
Sensitivity:   Non-reactive – Responsive as sun and warmer temperatures dominate
Distribution:   Specific
Likelihood (Human Triggered): Possible
Size:   Small 
Danger Trend:   Increasing with solar input and warmer temperatures
Forecaster Confidence:    Good

Persistent Slab:
Elevation:   Above 4000′
Aspect:  All
Terrain:   Above 32 Degree Slope Angle
Sensitivity:  Stubborn
Distribution:   Widespread
Likelihood (Human Triggered): Possible
Size:   Large
Danger Trend:   Steady
Forecaster Confidence:    Poor

AVALANCHE PROBLEM TOOLBOX <here>

SNOWPACK DISCUSSION: Snowmachine triggered avalanches will be in the afternoon when the day time temperatures have reached above 32 degrees F. Numerous point release wet avalanches and wet slab avalanches have been triggered by sledders on south facing slopes. Although they are slow moving, these wet avalanches will easily entrain you into the snow.

There is still a potential weak layer lurking on the north facing slopes at high elevations. If you will be climbing into the north facing slopes of mountains like Courage, No Name Glacier, College Glacier, or the Gakona Glacier you could trigger a persistent slab avalanche. Although likelihood is low, the consequences are high.

Recent Avalanche Activity

Numerous wet slab Avalanches were snowmachine triggered Thursday afternoon in areas like Gun Creek and on the big south facing mountain to the west of camp.

Recent Weather

Recent daytime temperatures have reached into the upper 30’s. Night time temperatures are forecasted to drop into the high teens. Friday morning will bring sunny skies with a chance of snow in the afternoon.  Daytime temperatures reaching close to 40 degrees F. Read the whole Arctic Man spot forecast issued by the National Weather Service Here

Additional Info & Media

SNOW HISTORY: Valdez 2/24 AM Thompson Pass 2/24 AM
24 Hour Snow / Water Equiv. <0″/0″ 0″ /0″
Storm Snow /Water Equiv. (2/22-2/23) 0.6” /0.05″ 1″ /0.1″
Current Snow Depth 48″ 49″
February Snow / Water Equiv. 44.9″ /5″ 43″ / 5.1″
Total Winter Snowfall / Water Equiv. 222.8″ /20.9” 282″ / 27.7″
Snowload in Valdez ~ lbs/sq. ft.

 

SNOWFALL at OTHER STATIONS:
LAST 24 HRS (2/24 AM)/STORM TOTAL (2/22-23)/STORM WATER EQUIV.:
Nicks Valley at 4200 ft (in): 0″ / 0″ / 0″
Upper Tsaina at 1750 ft (in): 0″ / 0″ / 0″
Sugarloaf at 550 ft (in): 0″/ 1″ / 0.1″
SNOW DEPTH & WATER SURVEY (2/1/2017) Depth Snow Water Equivalent
Milepost 2.5 Valdez  41.5″  9.8″
Milepost 18 43.9″ 9.5″
Milepost 29 Worthington Flats 61.5″ 16″
Milepost 37 Tsaina River bridge 42.1″ 9.3″
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 EARAC Forecasts.
Pete Carter

Forecaster: Pete Carter