Tuesday – Friday 3/21-24

Issued: Tue, Mar 21, 2017 at 8AM

Expires: Fri, Mar 24, 2017

North winds are back. These winds will stiffen up the fresh powder into a slab. Look for wind loaded slopes and play with caution.

Join the VAC Basecamp FREE classes every day this week in the One Love Lot (MP 29.5). Check our Facebook page for more details! Today’s class 3-5pm: Recognizing Avalanche Terrain

Above 2,500ft Considerable

1,800 to 2,500ft Considerable

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

 

 

WIND SLAB:
Elevation:  
Above 2000′
Aspect:
   Lee to northerly winds
Terrain:
 Near ridgelines, rollovers, and gully walls
Sensitivity:
  Reactive
Distribution:
 Specific
Likelihood (Human Triggered):
 Likely
Size:
 Small – Large
Danger Trend:
  Increasing
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: 

Certain Maritime zones have a variation of new snow from the last 48 hours. Cordova reported 8 inches at sea level yesterday AM, with 2 feet at 1000′, while the town of Valdez received 2 inches with 1 foot at the pass. If you head South, like to The Books or Marshall Pass, you might find deeper snow than in town or on the pass. More snow equals more fresh avalanches. While on the contrary more interior areas like the Tonsina Valley might have only seen a dusting.

The surfaces under the fresh powder are favorable for avalanches, and winds are picking up(45+ MPH) which will stiffen up this fresh powder into a cohesive slab. Look for fresh wind loaded slopes and limit your exposure on them. A snowmachine or a skier could easily pop off a fresh windslab that could bring you into a terrain trap.

Rain Crust from mid Feb. is a bed surface under the couple inches of new snow.

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

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

  • Expect new windslab to be sensitive to human trigger.
  • March 7 report of two human triggered size D1 soft slab avalanches (3500’ SW 20cm and 4000’ NE 15cm). Plus long running dry loose and several collapses on low angle terrain.

Recent Weather

See Maritime Zone for updated weather.

Additional Info & Media

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 Intermountain Forecasts.
Kyle Sobek

Forecaster: Kyle Sobek