Valdez
Above 4,000ftModerate
2,000 to 4,000ftModerate
Below 2,000ftLow
Degrees of Avalanche Danger
Avalanche Problems
Problem 1
The 1/14 buried surface hoar that was the weak layer responsible for the most recent natural avalanche cycle has been found on all aspects above 2500′ in the intermountain and continental zone, but not the maritime zone. This layer is buried 1.5-3 feet in depth and has produced propagation in stability tests as recently as 1/28, although results have been mixed. Identifying the 1/14 BSH is becoming increasingly difficult as it is now laid flat, is rounding and the weight of the slab above has been mixing with the snow beneath. The likelihood of triggering an avalanche at this layer is decreasing as temperatures have been mild, and we haven’t received any major loading by precipitation or wind in the last 7 days. If you were to trigger an avalanche at this layer, wide propagation would be expected as the overlying slab has settled and become dense (4 finger-1 finger).
Signs of instability may not exist even in areas where triggering an avalanche is a possibility. Persistent weak layers are unfortunately just as their name describes them, persistent. Avalanches can occur at this interface long after the layer is buried. Although, signs are pointing to this layer healing and becoming less reactive. We are going to keep this layer on our list due to the snow grain that is involved and the large size of avalanches that would occur should this layer be triggered.
Likelihood:
- Almost Certain
- Very Likely
- Likely
- Possible
- Unlikely
Size:
- Historic
- Very Large
- Large
- Small
Trend
- Increasing
- Steady
- Decreasing
Problem 2
Weak snow exists near the base of our snowpack in all three climate zones. A step down avalanche occurred during the 1/23-25 storm on Nicks Buttress (see avalanche activity section). The was the first activity at this layer since 1/6, but does show that weak snow near the base of the snowpack can still produce avalanches.
Faceted snow near the ground has been found to vary significantly from place to place. In most locations this snow has been found to be rounding (gaining strength) and unreactive in stability tests. In thin areas of the snowpack these facets are significantly more developed. On 1/31 a very thin snowpack was found (28-36 inches) ~4000′ on Nicks buttress/North aspect. Stability tests produced propagation near the ground failing on 6mm depth hoar. The most likely places to affect weak snow near the ground will be in areas where the snowpack is thin.
Tracks on a slope are not a sign of stability with this problem.
Depth hoar from Nicks Buttress ~4000′ North aspect 1/31.
Likelihood:
- Almost Certain
- Very Likely
- Likely
- Possible
- Unlikely
Size:
- Historic
- Very Large
- Large
- Small
Trend
- 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.
No avalanches reported or observed in the last 7 days.
Weather
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
NONE NWS Point forecast for Thompson Pass
Date Thursday 02/02/23 Friday 02/03/23 Time (LT) 06 12 18 00 06 12 18 00 06 Cloud Cover OV OV OV OV OV OV OV OV OV Cloud Cover (%) 100 90 85 85 90 80 90 85 85 Temperature 21 23 23 20 20 22 22 18 18 Max/Min Temp 25 19 24 18 Wind Dir E SE S SE SE SE SE SE E Wind (mph) 3 2 2 3 3 3 2 2 3 Wind Gust (mph) Precip Prob (%) 80 50 10 30 40 30 30 20 60 Precip Type S S S S S S S S 12 Hour QPF 0.14 0.03 0.06 0.05 12 Hour Snow 1.1 0.0 0.0 0.0 Snow Level (kft) 0.5 0.4 0.2 0.2 0.1 0.0 0.0 0.0 0.0
Click on link below for Thompson Pass weather history graph:
| Date:
02/02 |
24 hr snow | HN24W* | High temp | Low temp | 72 hour SWE* | February snowfall | Seasonal snowfall | Snowpack Depth |
| Valdez | 1 | .1 | 33 | 29 | .1 | 1 | 146 | 41 |
| Thompson pass | 0 | 0 | 18 | 15 | 0 | 0 | 286 | 48 |
| 46 mile | N/O | N/O | 25 | 15 | N/O | N/O | ~66** | 38 |
*HN24W- 24 hour Snow water equivalent in inches
*SWE– Snow 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.
Announcements
The avalanche hazard is Moderate above 2000 feet and low below for the Intermountain and Continental zones. It remains possible to trigger an avalanche 1.5-3 feet deep. Avalanches may be able to step down to deeper layers in the snowpack in isolated locations. Shallow instabilities may also exist near high elevation ridge lines. Areas where the snowpack is thin, steep convex or unsupported terrain will be the most likely areas to trigger an avalanche.
Posted by Gareth Brown 02/02 7:20 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.