|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.
With the sunny skies and increasing daylight hours, travel to the upper elevations in search of dry snow may be on some folk’s mind (if you are willing to brave the crust in order to get there – and back). Snow cover above 3,000′ has greatly improved after the January onslaught and is capped with 4-6″ of soft snow. The exceptions are those areas that avalanched to the ground. The last known deep slab was six days ago on Goat Mtn.
The reason we had such a widespread large avalanche cycle with slides breaking full-depth was because of weak snow near the ground that formed in November and December. We are four days past the end of the cycle yet it is still uncertain how well the weak faceted snow is adjusting to the new load. We know it is buried over 3 feet deep and likely much deeper in areas. This makes triggering a deep slab avalanche hard but it is not out of the question. Thin spots in the slab are the most likely trigger areas and can be commonly found near rocks and scoured terrain features.
Though the deep slab problem is by far the most concerning due to the potential consequences, wind slabs will be the most likely avalanche issue encountered above 3,000 feet. We found a few of these yesterday on all aspects yet they were quite small (around 2″ thick and 10′ wide). They were very reactive however and if you are traveling in the upper elevations where dry snow exists, I’d be on the lookout for any fresh wind deposited snow, especially that which is sitting on a slick surface.
With almost three days now of below freezing temperatures the pack is developing a healthy crust on the surface. These conditions are confined to elevations below 3,000′. Yesterday we dug (or maybe chopped is a better word) into the crust at 2,500′ and found it to be 1 foot thick. Underneath it remains 1-2 feet of wet and weak snow. The area we looked at yesterday was shaded and a place suspected to have a thicker crust than southerly slopes where Kevin dug two days ago. Check out Kevin’s video that shows just how weak the wet snow is.
This ‘hole’ (akin to an ice fishing hole) give a sense of the thick crust over wet snow situation (2,500′, W aspect).
Though the crust is getting thicker by the day and triggering a wet slab avalanche below treeline is becoming unlikely, we do have an unusual set up. As the ol’ timers say – unusual things can happen with unusual situations. Wet slabs with a crust on the surface have occurred before.
All that said, the greatest hazard below 3,000′ is slide for life conditions.
Yesterday’s weather consisted of blue bird skies, cool temperatures and light Northwest winds. Temperatures at 1,000′ were in the mid 20’s F and the upper teens at 4,000′.
Today is expected to be very similar. Skies have remained clear overnight, excect for some patchy fog in low-lying areas. A slight inversion is setting in and temperatures this morning at sea level and the ridgetops are both in the mid 20’s F. We should see a slight warm up to around 30F below treeline during the day. Winds are expected to remain around 10mph on ridgetops from the Northwest.
As for the extended forecast – it looks like this blocking high pressure will remain over mainland Alaska through the weekend.
Warmest January on record? With two weeks of rainy weather and at least one all time high temperature in the Girdwood Valley, we may just break the record for the warmest January. More on this in the next couple days.
|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
|Observation: Tincan Trees
|Dalpes/Thamm/ Schauer Forecaster
|Observation: Seward Highway across from Johnson Pass TH