Valdez
Above 3,000ftModerate
1,500 to 3,000ftModerate
Below 1,500ftModerate
Degrees of Avalanche Danger
Avalanche Problems
Problem 1
Currently, in many areas 6-12 inches of uncohesive (no slab) snow sits atop a layer of unreactive wind damaged snow. Human triggered avalanches up to 1 foot+ deep will be possible on lee aspects that have been loaded with this new snow by recent winds, creating cohesive snow (slab). Wind slabs could exist on a variety of aspects due to changing wind directions. Although, will be more sensitive on slopes loaded by E-SE winds, as this has been the most current direction of winds.
Stability assessment should be fairly straightforward today. Watch for where and if recent wind has redistributed new snow. Hard snow over soft at the surface, shooting cracks, and collapsing are all indicators of a wind loaded slope with the potential to produce an avalanche. Terrain to be cautious of includes: lee side of high elevation ridge lines, cross loaded gullies and steep convex terrain.
The hazard will be lower in areas where surface snow is unaffected by wind.
Likelihood:
- Almost Certain
- Very Likely
- Likely
- Possible
- Unlikely
Size:
- Historic
- Very Large
- Large
- Small
Trend
- Increasing
- Steady
- Decreasing
Problem 2
Faceted snow near the base of the snowpack has been identified in all three forecast zones. In most locations above brush line, faceted snow is capped by pencil-knife hard wind affected snow. This has created a strong bridging affect above 3000′, making a person or machines weight unlikely to directly affect these layers.
It has been 12 days since the last significant snowfall event, and stability tests that directly target these layers have not been producing significant results lately.
Persistent weak layers are tricky to assess and are notorious for surprising people. As long as temperatures remain cold and our snowpack is thin, these weak layers will continue to lose strength. It is likely that facets will reactivate in the future when stress is being applied through dramatic changes in weather such as: significant snow accumulation or rapid warming. Maintaining safe travel protocols such as skiing one at a time and avoiding traveling in or above terrain traps will increase your safety margin.
The most likely areas to trigger a persistent slab avalanche would be in steep terrain that was protected from previous strong winds that have occurred this season. This could be below brushline in steep open places, or in areas of terrain that are typically spared from outflows. The Continental zone remains suspect as this area has a weaker snowpack and generally receives less wind, which would decrease the bridging affect mentioned above.
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 recent avalanche activity has been recorded 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
...POTENTIAL FOR STRONG LOW TO BRING WINDS AND WINTRY MIX TO SOUTHCENTRAL THIS WEEKEND... We are monitoring the potential for an impactful weather event to occur across Southcentral this weekend. Weather models have not been consistent over the last 48 hours, which has resulted in lower forecast confidence, however, all models are keying in on a strengthening area of low pressure that will move from the north Pacific into the western Gulf sometime late Saturday night into early Sunday. This low has the potential to bring strong, gusty easterly winds to much of the northern Gulf, including Kodiak Island. Accompanying this area of low pressure is a deep fetch of moisture which will introduce warmer temperatures. This may result in a wintry mix of precipitation including rain, snow, freezing rain, sleet, or a combination of all throughout the event. At this time, we are not certain about the exact timing, amount of precipitation, or which locations will see which types of precipitation. All of this depends on the track the area of low pressure will take, and we are continuing to analyze that information. Please monitor the forecast in the coming days. We will be making frequent updates as we work to refine these details.
NWS Point forecast for Thompson Pass
Date Thursday 12/29/22 Friday 12/30/22 Time (LT) 06 12 18 00 06 12 18 00 06 Cloud Cover BK BK BK OV OV OV OV OV OV Cloud Cover (%) 65 55 70 80 80 80 85 90 85 Temperature 15 10 9 5 9 14 17 19 19 Max/Min Temp 16 5 17 16 Wind Dir E NE NE NE NE E E SE SE Wind (mph) 6 8 9 9 9 3 3 4 3 Wind Gust (mph) 20 25 26 27 24 20 Precip Prob (%) 5 10 5 0 5 10 30 60 40 Precip Type S S S 12 Hour QPF 0.00 0.00 0.00 0.08 12 Hour Snow 0.0 0.0 0.0 1.0 Snow Level (kft) 0.0 0.0 0.0 0.1 0.2 0.0 0.2 0.1 0.2
Click on link below for Thompson Pass weather history graph:
Date:
12/29 |
24 hr snow | HN24W* | High temp | Low temp | 72 hour SWE* | December snowfall | Seasonal snowfall | Snowpack Depth |
Valdez | ~3 | N/O | 32 | 26 | ~.3 | 59 | 94 | 39 |
Thompson pass | 1 | .05 | 27 | 23 | ~.55 | 89 | 190 | 24 |
46 mile | N/O | N/O | 11 | 5 | N/O | ~25 | ~34** | 29 |
*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. Once again, the hazard today primarily involves windslabs. Avalanche hazard will be concentrated to areas where the new 6-12 inches of low density new snow has been loaded by recent winds. Human triggered avalanches up to 1 foot in depth are possible in specific terrain, natural avalanches are unlikely.
Posted by Gareth Brown 12/29 7:30 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.