|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.
There are 2 interfaces in today’s snowpack that may act as sliding layers. They can be separated out by the 2 storms we’ve seen this week.
Storm snow that started falling last night may slide at the old surface layer we were skiing on yesterday. Yesterday we had a sunny break in the weather that built sun crusts on southerly aspects. With new snow building, this could become a sliding interface.
This morning the new storm snow is less than a foot deep, but is expected to reach closer to 2 feet by the end of the day.
Monday’s storm fell on the old February crust, which has some buried surface hoar acting as a weak layer above the crust. Yesterday we experienced frequent collapsing (whumphing) on this layer at elevations between 1000 and 2500 feet. Some avalanche activity on Tuesday was reported up to 2 feet deep from this storm.
A worst case scenario today would be avalanches that slide 3-4+ feet deep at the crust interface. This would include snow from both storms this week.
The storm that ended Tuesday dropped about 2 feet of snow in Girdwood and Turnagain Pass. That snow transitioned to rain at lower elevations at the end of the storm.
This morning, Center ridge weather station has already recorded about 9 inches of snow and up to 0.8 inches of water equivalent. Sunburst station saw wind gusts to 105mph overnight from the East.
Snow/rain line is predicted to stay at sea level today, but temperatures are right on the threshold. Some rain is possible at sea level. Snow above 1000 feet is expected to reach 11-16 inches today and another 9-14 inches tonight. An east wind will stay strong while this storm continues.
|Observation: TinCan Backdoor/ Center Ridge
|AAS L1 Turnagain
|Avalanche: Lynx Creek
|Observation: Turnagain, Seattle, Mt Ascension
|Silverton Mountain Guides
|Observation: Tincan Trees
|Dalpes/Thamm/ Schauer Forecaster
|Observation: Seward Highway across from Johnson Pass TH
|Avalanche: Base of Seattle Ridge
|Troy Tempel, Thomas Lees, .Josh Bollaert, Damian Naquin
|Observation: Lynx creek
|Observation: Tincan Trees
|Moderow / Clayton