Forecast Expired - 01/22/2023

Above 4,000ftConsiderable

2,000 to 4,000ftModerate

Below 2,000ftModerate

Degrees of Avalanche Danger

Avalanche Problems

Problem 1

Storm Snow:

On 1/20 moderate to heavy snow along with moderate to strong north winds continued on Thompson Pass and areas to the north.  The depth of snow on top of the 1/14 buried surface hoar layer is increasing with sensitivity expected to increase as well. 


At this point it is unclear if the 1/14 BSH layer will remain intact and be a future problem, or if it will be absorbed into the soft snow beneath.  It would be prudent to be in an assessment mindset for the time being.  Watch for signs of instability such as shooting cracks or recent slab avalanche activity that would indicate that a weak layer exists in our upper snowpack.  Digging snowpits and using small test slopes are both great ways to get a feel for surface stability.


At this point it is clear that a foot or more of snow has fallen along with moderate to strong north winds.  This on its own is enough to make specific slopes prone to human triggers 1-2 feet in depth.  Freshly wind loaded slopes where storm slabs are deeper and stiffer are going to be the most dangerous today.  


The snowpack at the surface is undergoing some moderate changes, and will need time to adjust.  In the meantime human triggered avalanches will be likely in specific areas.


  • 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 15 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

1/20- Numerous large (D2) wet loose avalanches released from steep planar slopes in the Port of Valdez.  These were caused by a foot or more of snow falling with temperatures rising to 40° F at sea level directly following.  No step downs noted.

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

NWS Point forecast for Thompson Pass
A 20 percent chance of snow before noon. Mostly cloudy, with a temperature falling to around 16 by 10am. North wind 25 to 30 mph.
Mostly cloudy, with a low around 7. Northeast wind 25 to 30 mph decreasing to 15 to 20 mph after midnight.
Snow likely, mainly between noon and 3pm. Cloudy, with a high near 26. East wind 5 to 10 mph. Chance of precipitation is 70%. New snow accumulation of less than a half inch possible.
Sunday Night
Snow. Low around 21. Northeast wind 5 to 15 mph becoming southeast after midnight. Chance of precipitation is 80%.
Snow. High near 30. Southeast wind 10 to 15 mph, with gusts as high as 20 mph. Chance of precipitation is 100%.
Monday Night
Snow. Low around 26. South wind around 15 mph, with gusts as high as 20 mph. Chance of precipitation is 90%.
Detailed forecast for Thompson Pass Mid elevation (2000-4000 Feet)
Date               Saturday 01/21/23       Sunday 01/22/23         
Time (LT)          06    12    18    00    06    12    18    00    06
Cloud Cover        OV    BK    OV    OV    OV    OV    OV    OV    OV
Cloud Cover (%)    75    65    70    70    90    95    95    95   100
Temperature        23    19    15     9    17    23    25    22    25
Max/Min Temp                   24           9          25          22
Wind Dir            N    NE    NE     E     E    SE     E     E    SE
Wind (mph)         16    19    16     6     6     8    12    12    10
Wind Gust (mph)                27                                    
Precip Prob (%)    20    10    30    20    50    70    70    70    80
Precip Type         S     S                 S     S     S     S     S
12 Hour QPF                  0.03        0.04        0.11        0.20
12 Hour Snow                  0.0         0.0         0.7         3.3
Snow Level (kft)  0.0   0.0   0.0   0.0   0.1   0.2   0.3   0.8   1.0
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 0 0 41 32 N/O 39 136 54
Thompson pass  N/O N/O N/O N/O N/O 63 250 44
46 mile 8 .52 25 13 N/O 32 ~66** 42



*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 4000′ and Moderate below.  Human triggered avalanches are likely in specific areas 1-2 feet in depth.  Storm slabs continued to build on 1/20 that are stressing weak snow.  Moderate north winds have loaded lee slopes deeper, making human triggered avalanches likely in these areas.

Posted by Gareth Brown 01/21  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.