|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 were two small human-triggered avalanches reported yesterday. One was a skier-triggered slab in the Goldpan area up above Magnum and Cornbiscuit. The avalanche was small and the skier was not caught. The other was a very small snowmachine-triggered slab in Lynx creek, which either occurred Saturday or Sunday.
A group skiing in Pete’s North yesterday observed a large collapse just above treeline. This didn’t lead to an avalanche, but it is the third observation in two weeks noting concerning structure that seems to be confined to Pete’s. We don’t usually forecast for such a specific piece of terrain, but it seems like there is cause for concern in that area right now that doesn’t exist for most of the rest of the advisory area.
|Size (D scale)
|Unlikely to bury a person
|Can bury a person
|Can destroy a house
|4 & 5
|Can destroy part or all of a village
Temperatures are on the rise again today, and uncertainty is high with just how the snowpack will respond. It is likely we will see some loose snow avalanches as things heat up later in the day. This should start out with rollerballs releasing near rocks and trees, which will likely start to entrain loose snow at the surface as the snowpack warms. This type of activity was observed yesterday, and we should expect more of the same today. These loose snow avalanches should be on the smaller side, and can easily be managed by avoiding steep southerly terrain later in the day. The first sign of deteriorating conditions will be those rollerballs- small chunks of snow rolling down steep terrain. If you notice that kind of activity, it is time to move to shaded terrain.
The bigger question will be how the snowpack responds just below the surface. There is a chance that a loose snow avalanche near the surface could pull out a bigger slab. This may be a stubborn wind slab that formed towards the end of last week, or even one of those weak layers in the upper 2-3′ of the snowpack that have been mostly unreactive. Yesterday we noted two small human-triggered avalanches in steep alpine terrain, and similar activity will be possible again today. This is the beginning of the first major warming event of the season, and we need to be paying attention to changing conditions as things heat up later in the day.
Cornice Fall: Cornices are going to heat up just like the rest of the snowpack. This will make them more tender, making natural cornice falls possible and making it even easier for a person to cause one to break. A falling cornice can be dangerous enough on its own, but there is a good chance that a falling cornice will trigger a slab avalanche as it tumbles down the hill. People noticed a cornice-triggered avalanche that was a few days old near Captain’s Chair yesterday, and there was similar activity on Goat Mtn. above Girdwood as well.
Dry Loose Avalanches (Sluffs): It is likely people will trigger sluffs in steep terrain with soft, dry snow on the surface. It is unlikely these will be big enough to bury a person, but they can be dangerous in consequential terrain where a fall would carry you over rocks, cliffs, or through trees.
Glide Avalanches: We received reports of fresh glide activity in the Summit Lake area yesterday. As temperatures continue to climb over the next few days, we may see more glide cracks open up and we may even see some glide avalanches release. These are impossible to predict and are very large and dangerous. The good news is that they are easy to manage by simply avoiding spending any time below glide cracks.
Rollerballs in steep southerly terrain in the Spokane Creek drainage yesterday. This will be the first sign that stability is deteriorating, and it is time to seek out shaded slopes. Photo: Alaska Guide Collective. 03.05.2023
Debris from loose snow avalanches below just about every gulley in the Library yesterday. Similar activity is likely as warm temperatures continue today. Photo: Rachel Heath, 03.05.2023
As mentioned above, we are still keeping the weak layers of snow in the upper snowpack on our radar for now. For the most part, it seems these have become unreactive for most of our advisory area. The most concerning places where these weak layers may still be lingering are in the zones with a thinner snowpack. We’ve seen multiple observations pointing towards reactive weak layers towards the south end of Turnagain Pass and Summit Lake, and we suspect there may be similar structure towards Crow Pass. As the snowpack heats up today and tomorrow, it is worth keeping these layers in mind while you are choosing your terrain.
Yesterday: Winds were light out of the north at 5-10 mph with gusts from around 10-15 mph. Skies were mostly sunny, with some high clouds moving in during the afternoon. The coldest temperatures in the past 24 hours were yesterday morning, with temps in the single digits F in the valleys and in the low teens F at higher elevations. High temperatures made it up into the mid 20’s F at lower elevations and up into the mid 30’s F near ridgelines. As of 5:00 this morning, temperatures are in the mid teens to low 20’s F in the valleys and in the upper 20’s to low 30’s F at higher elevations. We did not receive any precipitation yesterday.
Today: The temperature inversion continues to build today, with high temperatures expected to reach the mid to upper 30’s F, and the warmest temperatures around 3000’-5000’ elevation. Winds should be light out of the northwest around 5 mph with gusts around 10 mph. Skies will be partly cloudy with some upper level clouds, and no precipitation is expected today.
Tomorrow: The inversion continues to build tonight into tomorrow. It is likely we will see temperatures stay above freezing tonight, with daytime highs tomorrow possibly getting into the 40’s F between 3000’-5000’. Skies should be mostly sunny with light westerly winds. No precipitation is expected tonight or tomorrow.
PRECIPITATION 24-hour data (6am – 6am)
|Temp Avg (F)
|Snow Depth (in)
|Center Ridge (1880′)
|Summit Lake (1400′)
|Alyeska Mid (1700′)
|Bear Valley – Portage (132′)
RIDGETOP 24-hour data (6am – 6am)
|Temp Avg (F)
|Wind Avg (mph)
|Wind Gust (mph)
|Seattle Ridge (2400′)
|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
|Avalanche: Base of Seattle Ridge
|Troy Tempel, Thomas Lees, .Josh Bollaert, Damian Naquin
|Observation: Lynx creek