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The avalanche danger is MODERATE above 1,000′ on all aspects. Triggering a shallow wind slab avalanche will be possible on wind loaded slopes and cross loaded gullies. There is also the possibility for a person to trigger a larger slab that breaks in weak snow 1-2′ deep. The danger is LOW below 1,000′ where triggering an avalanche is unlikely.
Coming up this Friday night, Feb 16th – The 2018 SNOWBALL!! Join the CNFAIC, our non-Profit Friends group and Alaska Avalanche School for live music by the Hope Social Club, silent auction, raffle, locally brewed beer and good people. This benefit supports avalanche safety in Southcentral Alaska, we look forward to seeing you there!!
Coming up Saturday, Feb 17th, from 11am-1230pm – Free Avalanche Beacon Practice with CNFAIC! We will be hosting a short workshop on how to effectively perform a companion rescue. Open to all users and all levels; swing by on your way to the hills if you are just getting into avalanche safety or simply need a refresher!
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 |
Yesterday’s sunny skies revealed what most of us powder lovers do not wish to see after a snowfall event…wind. Monday night and Tuesday morning North and West winds wreaked havoc on much of the terrain around Turnagain, Summit Lake, Portage and the Girdwood Valley. Wind scalloped many snow surfaces, scoured some ridgelines to the rocks and sastrugi was reported on Tincan. Along with the winds, no natural avalanche activity was seen in the Turnagain area, but the Summit Lake region saw several shallow natural wind slab avalanches along with one that appeared to step down into an older weak layer.
For today, our main avalanche concern centers around a person triggering a large persistent slab avalanche up to 2′ or more in depth. Below the storm snow and recent wind slabs (addressed below) sits the Jan 21 buried surface hoar we have been talking about for some time. This layer is roughly 1-2′ below the surface and with recent wind and snowfall adding stress to it, the possibility for a person to tip that balance and initiate a larger slab avalanche is possible. There is also the possibility that a small wind slab or cornice fall could trigger this layer. We are back in a regime where no signs of instability are likely to be present before one of these avalanches releases and snowpit tests become unreliable. Therefore, assessing your terrain and the potential outcome if an avalanche breaking deeper in the pack does occur is key. Are there terrain traps below you? Cliffs? Are your partners watching and rescue ready? As we head into another period of high pressure (after today) keep these things in mind.
Northerly winds creating plumes off of Tincan Proper yesterday morning. (Photos: Jessie Haffener)
Anti-tracks on Tincan
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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 |
Watch for wind slabs to be lurking intermixed with the variable surface conditions on the steeper slopes. These will likely be shallow, up to a foot thick, and stiff. They should be easy to identify with a rounded shape and hollow feeling. Watch for shooting cracks and places the wind crust becomes thicker. Cross loaded gullies could be a good place to find and trigger a wind slab as winds did blow at all elevations.
Image below of a shallow wind slab on Tincan yesterday. Small terrain, small avalanche – Large terrain, small to large avalanche with higher consequences.
Above 3,000′ in the Alpine zones, several old weak layers of facets and buried surface hoar sit near the ground and in the mid-pack. This structure is most pronounced in areas with a thin overall snow cover, such as the South end of Turnagain Pass and the Summit Lake area. Recent wind slab avalanches Monday on Fresno ridge (Summit Lake zone) look as if they ‘stepped’ down into older weak layers in the snowpack. This is noteworthy and a reminder not to forget there are lurking old layers that could ‘wake up’ if one hits just the wrong spot.
Pictured below are shallow wind slab avalanches on Southeasterly facing Fresno ridge that looked to have triggered a deeper weak layer and subsequent larger avalanche lower on slope in the trees. (Photo: Jessie Haffener)
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Sunny skies along with strong West the North ridgetop winds were over the region yesterday. Seattle Ridge weather station recorded averages at 50mph from the North with gusts to 68mph. Wind decreased significantly over the day and was light and variable overnight. No precipitation fell and temperatures were in the mid 20’s along ridgetops and near 30F at 1,000′.
Today, Wednesday, a weak front is moving in with associated cloudy/overcast skies. There is a chance for a few snow flurries, but only a trace of accumulation is expected. Ridgetop winds are expected to pick up slightly from the Southeast and blow in the 10-15mph range. Temperatures will be near 30F at 1,000′ and remain in the mid 20’sF along ridgetops.
Sunny skies with generally light winds and cool temperatures are expected for Thursday and into the weekend. Northerly winds may pick up again on Saturday, stay tuned.
Temp Avg (F) | Snow (in) | Water (in) | Snow Depth (in) | |
Center Ridge (1880′) | 28 | 0 | 0 | 66 |
Summit Lake (1400′) | 22 | 0 | 0 | 25 |
Alyeska Mid (1700′) | 29 | 0 | 0 | 58 |
Temp Avg (F) | Wind Dir | Wind Avg (mph) | Wind Gust (mph) | |
Sunburst (3812′) | 22 | NW | 8 | 36 |
Seattle Ridge (2400′) | 27 | N | 20 | 68 |
Date | Region | Location | Observer |
---|---|---|---|
10/27/24 | Turnagain | Observation: Tincan | Michael Kerst |
10/21/24 | Turnagain | Observation: Turnagain Pass Road Observation | Trevor Clayton |
10/19/24 | Turnagain | Observation: Tincan – Below Todds Run | Andy Moderow |
10/18/24 | Turnagain | Observation: Taylor Pass | Eli Neuffer |
10/15/24 | Turnagain | Observation: Tincan Common | John Sykes Forecaster |
10/14/24 | Turnagain | Avalanche: Tincan | CNFAC Staff |
05/13/24 | Turnagain | Observation: Eddie’s, Sunburst, Seattle, Cornbiscuit, Pete’s South | H Thamm |
05/13/24 | Turnagain | Observation: Turnagain Pass non-motorized side | Amy Holman |
05/12/24 | Turnagain | Observation: Warm up Bowl | Tony Naciuk |
05/07/24 | Turnagain | Observation: Turnagain Pass Wet Slabs | A S |
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