Forecast Expired - 01/21/2023

Above 4,000ftConsiderable

2,000 to 4,000ftConsiderable

Below 2,000ftModerate

Degrees of Avalanche Danger

Avalanche Problems

Problem 1

Storm Snow:

In the last 24 hours Thompson Pass and Valdez have received 7-11 inches of heavy snow in low lying areas. Upper elevations are expected to have more.  On 1/19 northeast winds were stronger than forecasted, with moderate to strong winds redistributing new snow in the mid elevations of the Port of Valdez.  Top heavy storm slabs now exist 6 inches-2 feet in depth depending upon elevation and exposure to wind loading.  These storm slabs are loading the 1/14 buried surface hoar layer which will make surface snow more prone to triggers than it would normally be.  


The surface snow is expected to be sensitive on all aspects above 2000′, but will be the most dangerous on wind loaded slopes where deeper/ stiffer slabs exist.  The hazard will be increasing as winds are forecasted to increase today with gusts up to 40 mph.


Watch for signs of instability such as shooting cracks, collapsing and recent avalanche activity.  If these exist in the area that you choose to travel, then triggering an avalanche is possible in terrain steeper than 32°.


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


  • Historic
  • Very Large
  • Large
  • Small


  • Increasing
  • Steady
  • Decreasing

Problem 2

Deep Slab:

Faceted snow at the base of our snowpack has not been reactive for 14 days, on 1/6 one outlier avalanche occurred at mid elevation near Thompson Pass (see avalanche activity section).  Prior to this, avalanches haven’t occurred since 12/16 at these deep layers.


 Rounding (strengthening) has been observed at these facets in all three forecast zones, but this process takes a lot of time.  At this point triggering an avalanche at this layer is unlikely.  Once significant snowfall returns to our area, expect for the potential to affect these deep layers to increase.  The most recent storm is not expected to be big enough to affect deep persistent layers.


Unlikely does not mean impossible, and triggering an avalanche deep in the snowpack would carry significant consequences.  The most likely place to affect these layers would be in thin, rocky areas in the Continental zone.  



Rounding facets near the base of our snowpack from Cracked Ice at 4000′ on 1/11.


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


  • Historic
  • Very Large
  • Large
  • Small


  • Increasing
  • Steady
  • Decreasing

Avalanche Activity

Below is a summary of observed Avalanche activity from the last 7 days.  Avalanches that were noted earlier in the season can be viewed by clicking the link below.

If you trigger or observe a natural avalanche consider leaving a  public observation.

Valdez Avalanche Activity

1/17- Numerous wet loose point release were observed on solar aspects in the Port of Valdez.  Most of these originated from rocks were the suns energy permeated into dry snow and caused surface snow to become upside down.  No step down slab avalanches were observed.


-Small (D1) spin drift avalanches on the lee side of Tones Temple ridge triggered a small slab at the 1/14 BSH layer.



Check out our updated weather tab!  A collection of local weather stations are available for viewing with graphs and tabular data included.

NWS Watches and warnings

Northeast Prince William Sound-
Including the cities of Valdez and Thompson Pass
431 AM AKST Fri Jan 20 2023


* WHAT...Blowing snow expected. Northeast wind 15 to 25 mph with
  gusts to 35 mph. Visibility reduced to one half mile at times.
  Total snow accumulations of 2 to 4 inches.

* WHERE...Thompson Pass.

* WHEN...From noon to 9 PM AKST Friday.

* IMPACTS...Travel could be difficult.

* ADDITIONAL DETAILS...Gusty northeast winds will rapidly develop
  through Thompson Pass midday and strengthen through the
  afternoon hours. Light snow will overspread the area during the
  afternoon. Snow and increased winds will lead to low
  visibilities in blowing snow. Snow is expected to taper off
  through this evening, while winds will persist after midnight.
NWS Point forecast for Thompson Pass
Snow. Areas of blowing snow after noon. High near 29. Northeast wind 5 to 15 mph increasing to 15 to 25 mph in the afternoon. Winds could gust as high as 35 mph. Chance of precipitation is 90%. Total daytime snow accumulation of around an inch possible.
Snow, mainly before midnight. Areas of blowing snow before 9pm. Low around 13. North wind 20 to 30 mph, with gusts as high as 35 mph. Chance of precipitation is 80%. New snow accumulation of around an inch possible.
A 30 percent chance of snow before 9am. Partly sunny, with a temperature falling to around 13 by 10am. North wind 20 to 25 mph increasing to 25 to 30 mph in the afternoon.
Saturday Night
Partly cloudy, with a low around 2. Northeast wind 25 to 30 mph decreasing to 15 to 20 mph after midnight.
Snow likely, mainly after 3pm. Cloudy, with a high near 22. Southeast wind 5 to 10 mph. Chance of precipitation is 60%.
Sunday Night
Snow. Low around 21. Southeast wind around 5 mph. Chance of precipitation is 100%.
Detailed forecast for Thompson Pass Mid elevation (2000-4000 Feet)
Date               Friday 01/20/23         Saturday 01/21/23       
Time (LT)          06    12    18    00    06    12    18    00    06
Cloud Cover        OV    OV    OV    OV    OV    BK    SC    SC    OV
Cloud Cover (%)   100    95   100    85    85    60    40    35    80
Temperature        25    26    26    19    23    19    13     5    11
Max/Min Temp                   29          14          25           5
Wind Dir           SE    NE    NE    NE     N     N    NE    NE     E
Wind (mph)         10     8    23    16    18    17    16     8     4
Wind Gust (mph)          28    36                      29    25    17
Precip Prob (%)    90    80    80    50    30    10     5     0    10
Precip Type         S     S     S     S     S                        
12 Hour QPF                  0.15        0.10        0.02        0.00
12 Hour Snow                  1.6         1.5         0.0         0.0
Snow Level (kft)  1.4   1.2   0.5   0.3   0.0   0.0   0.0   0.0   0.0
Click on link below for Thompson Pass weather history graph:






24 hr snow HN24W* High temp Low temp 72 hour SWE* January snowfall Seasonal snowfall Snowpack Depth
Valdez 11 .6 35 23 .69 39 136 54
Thompson pass  7 N/O N/O N/O N/O 63 250 44
46 mile N/O N/O 15 6 N/O 24 ~60** 36



*HN24W- 24 hour Snow water equivalent in inches

*SWESnow water equivalent

**46 mile seasonal snowfall total begins December 1st.

Additional Information


Click on the link below for a running summary of the seasons weather history.

Valdez Weather History


The avalanche hazard is Considerable above 2000′ and Moderate below.  Human triggered avalanches are likely 1-2 feet in depth and natural avalanches are possible.  Upside down storm slabs are sitting on weak snow making human triggered avalanches likely in terrain steeper than 32°.  Strong north winds will load lee slopes, creating the potential for deeper slabs to be triggered.

Posted by Gareth Brown 01/20  8:00 am.


For a description of current avalanche problems, weather information, season history and more click the (+ full forecast) button.  Avalanche forecasts will be issued Wednesday-Sunday.

If you have pictures of recent natural or human triggered avalanches or notice signs of instability such as shooting cracks or collapsing, leave an observation to help improve forecast accuracy.