|Travel Advice||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.|
|Signal Word||Size (D scale)||Simple Descriptor|
|Small||1||Unlikely to bury a person|
|Large||2||Can bury a person|
|Very Large||3||Can destroy a house|
|Historic||4 & 5||Can destroy part or all of a village|
Strong easterly winds on Friday built stiff wind slabs 2-12’’ deep. Periods of moderate to strong easterly winds continued through the last few days and have distributed a variety of thin wind skins on mid and upper elevation SW through NW facing slopes.
Wind slabs will appear as smooth lenses or pillows on leeward or cross loaded aspects. They may sound hollow or crack out from your ski tip as you travel across them.
There are a variety of wind slabs out there to contend with, some are thick, firm, and edgeable, while others are thin, punchy, and grabby. For the most part these slabs are patchy in their distribution due to the overall lack of snow available for transport. On broad or convex slopes these pieces could be more firm, well connected, and easy to trigger.
As with the avalanche we observed yesterday, the possibility exists for these wind slabs to behave more like persistent slabs and break out above you or fail on deeper layers of the snowpack, up to 3′ deep.
As these slabs age they will become more stubborn and unreactive, meaning they could wait to release until you’ve found a thin spot on the slab. The structure exists for these slabs to fail on facet crust layers deeper in the snowpack, increasing the size and consequence of the avalanche.
Recent winds have contributed to the majority of conditions out there. The graph below shows that after their peak on Sunday, winds continued to gust into the 30’s this week and transport what little snow is left.
It’s currently snowing, with a trace to an inch of new snow expected today and continued light to moderate South/Southeasterly winds.
There looks to be increasing chances for more accumulations Friday with a quick hitting trough that will bring a period of strong snow and wind.
With changing conditions be sure to have a look at recent snowfall through the links below.
NWS AVG Forecast here.
NWS point forecast here.
Marmot Weather Station here.
Independence Mine Snotel here.
Frostbite Bottom Snotel here.
State Parks Snow Report and Motorized Access information here.
XC trail grooming report for Mat-Su, Anchorage, and Kenai here.