Valdez

Forecast Expired

Above 4,000ftHigh

2,000 to 4,000ftHigh

Below 2,000ftHigh

Degrees of Avalanche Danger

Avalanche Problems

Problem 1

Storm Snow:

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

Wind Slab:

Likelihood:

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

Size:

  • Historic
  • Very Large
  • Large
  • Small

Trend

  • Increasing
  • Steady
  • Decreasing

Avalanche Activity

12/30  Natural avalanche observed on Cracked Ice Butress at 2700′.  300 meters wide~, 1 meter+ deep~.  Connected through gullies and over ridges.

Reports of Natural avalanche on east face of Mt. Tiekel mp 50.

12/28- Several natural avalanches reported in the 54 mile area near brush line.  100′ wide and ran 300′.  Depth was not observed.

12/26- Skier triggered avalanche on Cracked Ice Buttress: N aspect, 2500′, 37° slope, 18 inches deep, 100 feet wide, ran 200-300 feet. SS-ASu-D1-R1-I

12/24- Skier triggered avalanche on Python Buttress: NW aspect, 2700′, 35° slope, 60 feet wide, ran 200-300 feet.  SS-ASu-D1.5-R1-O

12/18- A large glide release was reported off Snowslide Gulch middle peak size 2.5.

12/15- Observed small natural avalanche on west aspect of Goodwills.   Released below a cliff band at the bottom of a slope, 100′ wide.   SS-N-D1-N

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

12/31:  Snowfall continues for our area today with reports of very intense snowfall rates at Thompson Pass this morning.  An additional 1.5 inches of water is forecasted for the next 24 hours.   Temperatures are forecasted to drop overnight with moderate to strong winds out of the south.

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`      37 F         28 F

Temp at 3000`      33 F         23 F

Chance of precip   100%         100%

Precip amount
(above 1000 FT)    0.75 in      0.81 in

Snow amount
(above 1000 FT)    0-6 in       2-10 in

Snow level         2000 ft      1000 ft

Wind 3000` ridges  SE 6-27 mph  E 6-28 mph
 
  24h snowfall (inches) HN24W (inches)* Hi Temp (F) Low Temp (F) Dec snowfall Season Snowfall Snow height 
Valdez .5 1.33 33 31 53 70 32
46 mile 0 0 40 33 12

Thompson Pass “DOT”

11″ 30 26 96″

 HN24W= total water received last 24 hours in inches

Additional Information

We are developing the perfect recipe for avalanches: a bed surface, a weak layer, a slab and increasing temperatures.  The 12/9 rain crust will act as our bed surface.  Above the rain crust is our weak layer, a 5 cm layer of facets that has been created by the recent cold weather. Third is our slab, which has been created by snowfall that started 12/22, storm totals 110″ at Thompson Pass.  This slab is growing in size with continued heavy snow.  Temperatures rose significantly 12/29 and precipitation type has turned from snow to rain below 1000′.   Above 1000′, the snow has become heavier, which will create instability within the storm snow.  Human triggered and natural avalanches that happen within the upper snowpack could step down into lower layers and create very large avalanches.  Hazard will remain High until temperatures cool and significant snowfall stops.

 There have been limited observations from interior locations due to low snow at lower elevations.   Use caution if you travel in these areas.

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 High.

Video taken 12/20 in the Mt. Dimond area showing reactive test slopes.   https://vimeo.com/user106668057/review/380916811/02da5d1cc7

Alerts

The avalanche hazard is High today at all elevations on all aspects.  Natural avalanches are likely and human triggered avalanches are very likely.  Thompson Pass continues to receive significant snowfall, with 11 inches in the past 24 hours. Storm totals have exceeded 110 inches. Temperatures spiked on 12/29 creating dangerous avalanche conditions.  Avoid travel in avalanche terrain today.  Stay clear of avalanche runout zones.  The hazard will remain high until temperatures fall and precipitation tapers.