Valdez
Above 4,000ftModerate
2,000 to 4,000ftModerate
Below 2,000ftModerate
Degrees of Avalanche Danger
Avalanche Problems
Problem 1
Light snowfall has accumulated 6-10 inches since the 1st, depending upon distance from the coast and elevation. So far storm totals have been insufficient to create a slab that would significantly elevate the avalanche hazard, this may change over the next 24-48 hours.
Snowfall is expected to continue and may become moderate to heavy over the weekend especially near Valdez. Since multiple small storms have rolled through, expect for density changes (instabilities) to exist within the storm snow especially once heavier snowfall arrives. Signs of instability such as shooting cracks may be present if unstable snow exists, due to the instability being close to the surface.
In addition, there is a freezing rain crust that has been identified in the maritime and intermountain zones that extends into upper elevations. The distribution of this layer has been found to be spotty. As of 2/2 this layer has been found to have some energy in the maritime zone in stability tests, but is not yet buried by a sufficient slab to be an issue. This may become a problem layer in the future, in specific areas once additional snowfall arrives.
Likelihood:
- Almost Certain
- Very Likely
- Likely
- Possible
- Unlikely
Size:
- Historic
- Very Large
- Large
- Small
Trend
- Increasing
- Steady
- Decreasing
Problem 2
Surface hoar exists on all aspects above 2500′ in the Intermountain and Continental zones buried 2-3 feet deep. Stability tests have had mixed results as of late, with some areas showing propagation and others being unreactive to not present. The grain in question is becoming more difficult to locate, has showed signs of rounding (strengthening), laying flat, and being mixed with rounds from beneath. All signs are pointing towards this layer being dead or dormant. Except for the fact that surface hoar is notorious for surprising users and remaining reactive for long periods of time even after periods of dormancy.
We are leaving this layer on our list due to the potential for large to very large avalanches that would occur should this layer fail. This weak layer will be under increasing stress as moderate to heavy snow arrives this weekend. Once heavy snow arrives the likelihood of triggering an avalanche at this layer will be increasing.
Likelihood:
- Almost Certain
- Very Likely
- Likely
- Possible
- Unlikely
Size:
- Historic
- Very Large
- Large
- Small
Trend
- Increasing
- Steady
- Decreasing
Problem 3
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 / ~3500’/ north aspect (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.
If you find it is possible to push a ski pole to the ground in areas you travel. Assume that a weak faceted snowpack exists in that location, that could act as a trigger point.
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 an 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 Saturday 02/04/23 Sunday 02/05/23 Time (LT) 06 12 18 00 06 12 18 00 06 Cloud Cover OV OV OV OV OV OV OV OV OV Cloud Cover (%) 95 100 85 70 70 95 100 100 100 Temperature 16 21 20 15 14 19 20 19 21 Max/Min Temp 23 14 22 18 Wind Dir E E SW SE E E E S SE Wind (mph) 4 6 5 3 8 17 19 14 10 Wind Gust (mph) 32 34 36 Precip Prob (%) 60 100 60 20 20 50 90 90 100 Precip Type S S S S S S S S S 12 Hour QPF 0.19 0.05 0.14 0.46 12 Hour Snow 2.9 0.4 1.3 7.0 Snow Level (kft) 0.0 0.0 0.0 0.0 0.0 0.0 0.2 0.1 0.1
Click on link below for Thompson Pass weather history graph:
Date:
02/04 |
24 hr snow | HN24W* | High temp | Low temp | 72 hour SWE* | February snowfall | Seasonal snowfall | Snowpack Depth |
Valdez | ~2 | N/O | 33 | 27 | N/O | 1 | 146 | 41 |
Thompson pass | 9 | N/O | 24 | 13 | 0 | 0 | 286 | 48 |
46 mile | Trace | N/O | 21 | 13 | 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 at all elevations. It remains possible for a person to trigger an avalanche at weak snow that is buried 2-3 feet deep. There is also the potential that shallow instabilities exist near high elevation ridge lines and in steep terrain.
Posted by Gareth Brown 02/04 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.