Hatcher Pass
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The Bottom Line
The avalanche hazard is MODERATE today for Persistent Slab avalanches on all aspects and at all elevations up to D2 in size.
Expect persistent slabs to be stubborn to trigger and up to 1-4 feet deep.
In many cases, hard slabs are sitting on weak faceted snow and will be possible to human trigger. It may take large loads to trigger avalanches, such as groups of people, or snow machines, or just hitting the right thin spot in the slab to affect the weak layer.
Signs of instability may not be immediately obvious and will be difficult to detect without digging deeply into the snowpack and conducting instability tests.
Terrain choice will be key to staying safe in avalanche terrain this weekend. Choose smaller, lower angle terrain with good runnouts, lacking terrain traps. Ski one at a time, and use safe zones to spot each other. Avoid steep gully and creek sidewalls.
Special AnnouncementsThank you all for coming out to our Annual Cabin Fever Reliever. It was a success because of YOU!
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| 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. |
These natural avalanches were remotely triggered by a snow machine on Tuesday or Wednesday above Fish Creek, at the base of the road up to Hatcher Pass proper. A total of three avalanches were released (only two of three visible in photo). Although small slopes, these avalanches were deep, and funneled into open water terrain traps. If caught a person could have been buried, injured, or killed.
STEEP CREEK SIDEWALL – Remotely triggered slab avalanche by snow machine 100 feet away, size D2, some time between 2/11-12, Fishhook Creek, ENE, 2700′.
A significant avalanche cycle over the weekend of 2/8-10, produced widespread natural slab avalanches, mostly D2 with a few D3 ,on all aspects and at all elevations. Slab avalanches were deeper on leeward aspects, NW to E, and shallower on windward, SE to SW, aspects . Three avalanches crossed Archangel road, in addition to Marmot gullies 1 and 2 which just barely ran across the road between Archangel and Fishhook lot, up to D3 in size, likely sometime late Sunday or early Monday morning.
2/8-9 – Natural avalanche off Marmot crossed Archangel Winter Road/Trail, D3
2/9 – Peak x4068, NE, 3000′, Natural hard slab avalanche and sympathetic releases, viewers left D2.5 with crown estimated at 4´deep. Center picture of avalanche D1.5, right D1.
2/8-9 – Martin mine, E and ESE, 4650′?, D2.5
2/10 Observation of 2/8-9 Natural slab avalanche on Eldorado test slope, NE, 3250′, D2
2/8-9 – Delia creek ridgeline natural avalanches
2/8-9 – Natural slab avalanches in Rae Wallace Bowl, SW, 4650′
2/8-9 – Microdot, N,aspect 4500′, debris pile on Gold Cord Lake
| 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 |
Thick hard slabs formed by last week´s wind are sitting on faceted, persistent, weak layers in the snowpack, on all aspects, and at all elevations and will be the main problem this weekend and into next week.
This problem will be difficult to predict as the weak layers are deeply buried, 1-4 feet deep, and will require either large loads, or hitting just the right spot to trigger a dangerous, large avalanche. In isolated cases it may be possible to remotely trigger avalanches from a distance.
Last weeks 12″+ of new snow, in 1.3″ of SWE, and four days of strong winds formed slabs over a variety of weak, faceted layers, on all aspects, and at all elevations. There are some differences to note, such as thicker slabs on leeward aspects, generally NW to E, and shallower slabs on SE to W.
When we get out this weekend, we will generally be choosing slopes that lack firm, hard slab conditions under foot, and slopes that lack terrain traps. We will be vigilant about skiing one at a time and using safe zones to spot each other. When possible we will be avoiding larger, broad slopes. We will focus on smaller and lower angle slopes, and may give the avalanche problem a few days before venturing into steeper terrain.
Below is a video showing the depth of some of the more extreme hard slabs over weak layers we were able to observe this week:
Temps this morning at 2700-3050′ are in the teens with 10°F at 4500′.
Today at 3000′, temps are forecasted to remain in the teens, with light wind and variable wind direction.
Partly cloudy skies today with the best chance for good visibility being a window of opportunity on Sunday afternoon.
Sunday evening a change in the weather pattern should bring clouds, a chance for precipitation, and rising temperatures. Expect a chance for rain up to approximately 800-1000′ on Monday. Expect some precipitation in the next storm pulse begining Sunday evening, however, at this time, this storm system does not appear to be a big snow producer for HP.
The avalanche hazard will remain the same through the weekend unless we see significant weather events, such as strong winds, new precipitation and/or rising temperatures.
NWS Rec Forecast here.
NWS point forecast here.
State Parks Snow Report and Motorized Access information here.
