Valdez

Forecast Expired

Above 3,000ftModerate

1,500 to 3,000ftLow

Below 1,500ftLow

Degrees of Avalanche Danger

Avalanche Problems

Problem 1

Wind Slab:

Likelihood:

  • Almost Certain
  • Very Likely
  • Likely
  • Possible
  • Unlikely

Size:

  • Historic
  • Very Large
  • Large
  • Small

Trend

  • Increasing
  • Steady
  • Decreasing

Problem 2

Persistent Slab:

Likelihood:

  • Almost Certain
  • Very Likely
  • Likely
  • Possible
  • Unlikely

Size:

  • Historic
  • Very Large
  • Large
  • Small

Trend

  • Increasing
  • Steady
  • Decreasing

Problem 3

Glide Avalanches:

Likelihood:

  • Almost Certain
  • Very Likely
  • Likely
  • Possible
  • Unlikely

Size:

  • Historic
  • Very Large
  • Large
  • Small

Trend

  • Increasing
  • Steady
  • Decreasing

Avalanche Activity

 12/10-The only new natural avalanche activity in the Thompson Pass corridor was small, wet point-releases off the Nicks and Python Buttresses.  These originated from 3500-4000′ and did not entrain more snow.

12/8-  An observer witnessed a glide crack avalanche.  SW aspect of peak 4690′ above the Valdez Glacier Lake. The debris reportedly ran all the way to the lake, with the deposition pile only feet away from a well used cross country ski trail.

Weather

One to two inches of snow fell Friday night in the mountains. Winds were light to moderate out of the E/SE.

Saturday, expect an additional inch or two of snow in the morning hours before the current front dissipates.  Winds are forecast to be light to moderate for Thompson Pass, with highs in the mid 20’s.

The Thompson Pass Mountain Forecast covers the mountains (above
1000 ft) surrounding Keystone Canyon through Thompson Pass to
Worthington Glacier.

This forecast is for use in snow safety activities and emergency
management.

                   Today        Tonight

Temp at 1000`      34 F         27 F

Temp at 3000`      32 F         28 F

Chance of precip   100%         60%

Precip amount
(above 1000 FT)    0.19 in      0.04 in

Snow amount
(above 1000 FT)    0-3 in       0 in

Snow level         700 ft       500 ft

Wind 3000` ridges  E 2-12 mph   E 5-13 mph

  24h snowfall (inches) HN24W (inches)* Hi Temp (F) Low Temp (F) Dec snowfall Season Snowfall
Valdez .2 .43 39 22 7 31
46 mile 1 .1 21 12

Nicks snotel

(4500′)

1 29 21

 HN24W= total water received last 24 hours in inches

Additional Information

Wind slab is present off the lee side of ridges that are exposed to the wind.  On Thompson Pass, 1 finger windslab was present, extending 200′ below wind-exposed ridge lines.  Below this, the surface snow has much less wind affect.  Skiing slopes up to 35° has not found the windslab to be reactive.  With mild weather the last few days, the snowpack has gained strength.  The avalanche hazard is moderate today in the upper elevations.  It is still possible to trigger windslab avalanches up to 2′ deep.  Avoid convex, unsupported terrain and terrain traps.

 Below 3000′ there is a pencil hard rain crust and good stability.  

  If you venture into avalanche terrain today, use terrain progression as a tool.  Start with small slopes that have no consequence, before committing to larger slopes.

If you have traveled in the mountains, please leave a public observation.  The more info we can get from various locations will help us to get a clearer picture of the snowpack in our beautiful Valdez Chugach! 

Forecast Confidence is moderate.

Announcements

The avalanche hazard is moderate at upper elevations. Natural avalanches are unlikely today unless caused by a glide crack. Human triggered  avalanches are possible on  steep terrain, or in areas that have been affected by winds. Good indicators for windslab are a rapid increase in depth of the new snow over a short distance, shooting cracks and a hollow, drum-like feel. Use caution in the mountains today, watch for windslab and avoid terrain traps.