|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.
One more day of dust on crust conditions is on tap for the Pass and surrounding regions. Though we have a mostly stable snowpack and it has been over a week since we have seen/heard of any avalanche activity, there are a few things to keep in mind if you are venturing to the steep upper elevations. These are:
A bit on the snowpack:
The snowpack to date is composed of mostly crusts and weak snow near the surface. This, for the time being, is not a problem since there is no ‘slab’ portion to our pack. However, all bets will be off starting tomorrow as a much needed storm is on the doorstep. As we anticipate a new load, knowing the surface conditions is key. Currently, we are set up with a couple inches of weak faceted snow and surface hoar on top of a crust 1-4″ thick. This weak snow over a crust combo is a perfect weak layer and bed surface. Add a ‘slab’ of new snow on top of that tomorrow and it’s pretty easy to see that avalanche activity will be on the rise. It will be good to rein in the powder fever on the steeps this week.
During the past 23-hours (one hour less due to daylight savings time…) we have seen mostly clear skies and light winds from the west. Temperatures have averaged in the teens F at most locations. Overnight, temperatures have dropped to the low teens and valley bottoms have dropped even more to ~0F as a temperature inversion has set in.
Today will be the calm before the storm. Skies should remain mostly clear with high clouds streaming in for the afternoon. Temperatures will climb out of the single digits to near 30F at 1,000′ and up to 20F on the ridgetops. Winds will remain in the 5-10mph range and slowly shift from west to south to east through the day.
It looks like – after months of waiting – a series of ‘classic Chugach storms’ is on the way. Snowfall is expected to begin late tonight and pick up Monday. Models are showing around 1.5″ of water equivalent for late tonight through tomorrow night (that is 14-18″ of snow!). Add to that an additional 1″ of water (10-14″ of snow) for Tuesday. Snow should make it to sea level during this period but may rise to a rain/snow mix for Tuesday. These numbers are for Turnagain Pass and favored areas will likely see more and vice versa. Stay tuned.
With fear of reading too much into the crystal ball….models are showing another pulse of precip for Thursday/Friday and another for Saturday/Sunday.
|Observation: Bertha Creek
|Schauer/ Cullen Forecaster
|Observation: Magnum & Cornbiscuit
|Moderow / St. Clair
|Observation: Tincan Backdoor
|APU Snow Science I
|Observation: Silvertip Creek
|Observation: Seattle Ridge
|John Sykes Forecaster
|Observation: Kickstep NE Bowl
|Observation: TinCan Backdoor/ Center Ridge
|AAS L1 Turnagain
|Avalanche: Lynx Creek
|Observation: Turnagain, Seattle, Mt Ascension
|Silverton Mountain Guides