|Generally safe avalanche conditions. Watch for unstable snow on isolated terrain features.
|Heightened avalanche conditions on specific terrain features. Evaluate snow and terrain carefully; identify features of concern.
|Dangerous avalanche conditions. Careful snowpack evaluation, cautious route-finding, and conservative decision-making essential.
|Very dangerous avalanche conditions. Travel in avalanche terrain not recommended.
|Extraordinarily dangerous avalanche conditions. Avoid all avalanche terrain.
|Likelihood of Avalanches
|Natural and human-triggered avalanches unlikely.
|Natural avalanches unlikely; human-triggered avalanches possible.
|Natural avalanches possible; human-triggered avalanches likely.
|Natural avalanches likely; human-triggered avalanches very likely.
|Natural and human-triggered avalanches certain.
|Avalanche Size and Distribution
|Small avalanches in isolated areas or extreme terrain.
|Small avalanches in specific areas; or large avalanches in isolated areas.
|Small avalanches in many areas; or large avalanches in specific areas; or very large avalanches in isolated areas.
|Large avalanches in many areas; or very large avalanches in specific areas.
|Very large avalanches in many areas.
Without any reported natural avalanche activity again yesterday we have reason to believe that after a solid 12 days of rain and unseasonably warm temperatures the snowpack is adapting to this new normal. Natural avalanches will be less likely today but given the results from DOT and AKRR avalanche mitigation work along the Seward Highway yesterday, the faceted layer at the bottom of the snowpack is still proving to be quite reactive given the right (or large enough) trigger.
We still need several days and nights in a row with below freezing temperatures to really lock up the snowpack in these mid-elevations (1800’ – 3500’) where the vast majority of avalanche activity has occurred during this warm-up.
Below 1800’ our snowpack has literally deflated, losing perhaps 75% or more of its mass since January 15th due to rain and unseasonably warm temperatures. When travelling through this elevation band, avoid avalanche runout zones such as funneled terrain.
Peterson Creek path @ MP 84. Helicopter bombing triggered wet slab avalanche running on basal facets. Debris ran all the way to sea level even though the snow line is at approximately 1,000′.
Photo: Kevin Wright
Broken skies yesterday gave us a few brief glimpses of the high peaks around the Girdwood Valley. From the binoculars, winter appears to exist at these upper elevations (above about 4,000’) where the snow surface appears thick and plastered onto steep terrain in true Chugach fashion. With evidence of a deep slab avalanche cycle over the weekend there is still reason to be suspect of high elevation terrain as the deep slab problem is not one to heal itself quickly. If travelling into these upper elevations pay attention to what’s above you, including looming cornices which if released can act as a trigger large enough to initiate an avalanche.
Over the last 24 hours temperatures have continued a slow and steady decline at ridgetop locations with both Seattle Ridge and Sunburst maintaining temperatures below 32 degrees. Temps at sea level remained above average in the low to mid- 40’s. Winds continued out of the east averaging around 20mph. Precipitation was pretty limited with just a trace of rain and snow falling throughout the day. Rain/ snow line was around 2,000′ yesterday.
Temperatures today look to be in the mid-30’s at 1,000′ cooling to mid to low 20’s at ridgetop locations. We may see just a trace of precipitation today (with snow falling around 1,000′) as the current low pressure weakens and moves through our area. Winds will continue from the southeast in the 17-31mph range.
The trend for overnight and into tomorrow appears to be a building high pressure which should dry us out for a day or two though temperatures do not appear to drop dramatically.
|Dalpes/Thamm/ Schauer Forecaster
|Avalanche: Base of Seattle Ridge
|Troy Tempel, Thomas Lees, .Josh Bollaert, Damian Naquin
|Observation: Lynx creek
|Observation: Tincan Trees
|Moderow / Clayton
|Observation: Turnagain (below the uptrack)
|Alaska Avalanche School Moto Level 2
|John Sykes Forecaster
|Observation: Tincan Backdoor, Center Ridge
|AAS Level 1 / R Sullivan
|Avalanche: Tincan Trees
|Schauer/ Moderow/ Stephenson Forecaster