Hatcher Pass
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The Bottom Line
As of 5am this morning Hatcher Pass has received 6″ of new snow and .7″ water. With poor structure, this load will be enough to overload weak layers in the snowpack.
1.5 to 3.5 ft deep Persistent slabs will be likely to human trigger at all elevations, on all aspects, on slopes steeper than 30°. Natural avalanches are possible.
6″ to 9″ storm slabs will be likely to human trigger at mid and upper elevations, on all aspects, on slopes steeper than 35°. Natural avalanches are possible.
The forecast is calling for rising temps and 12″ to 15″ of snow Tuesday night thru Wednesday. Expect the danger to rise to HIGH with the additional load.
The road is closed at mile 11 at Hatcher Pass due to anticipated avalanche activity. Please respect this closure so avalanche danger can be assessed and mitigation can take place if needed.
Hatcher Pass Lodge snowstake at 6am this morning.
Special AnnouncementsToday is not typically a forecast day and it is the last day of our matching fund drive. If you value this life saving information, please help us out and donate today. The entire community thanks 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. |
Large natural and remotely triggered avalanches occurred on 2/13. Two of these avalanches were naturals, two were remotely triggered and those sympathetically triggered two other smaller avalanches.
The photos below show natural and remotely triggered large avalanches from 2/13. It is hard to see the crowns but they are there. All the avalanches occurred on the Arkose side and Punk Spines area from 3500-4000′ on SW,W,NW aspects.
| 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 |
Persistent slabs 1.5 feet to 3.5 feet will be likely to human trigger today on all aspects, at all elevations, on slopes steeper than 30°. Naturals will be possible. Large avalanches in specific areas or very large avalanches in isolated areas are expected today.
Hatcher Pass received 6″ of new snow and .7″ SWE overnight. We are excepting 2″-3″ more inches today before Wednesdays storm with rising temps and 12″ to 15″ additional snow. Today’s load will be enough to tip the balance, yet again, in the snowpack. We saw a similar storm on the 13th that produced large natural and remotely triggered avalanches.
The two layers of concern are buried and getting deeper in the snowpack. This means they are harder to trigger AND more consequential when triggered. The layers of concern are the Dec29 crust sandwich and the Nov sugary basal facets.
In many cases this season avalanches have released on both of these layers in the same slides. Avalanches may fail initially on crusts and then step down into the deeper basal facets near the ground, releasing the entire depth of the snowpack. The average depth of avalanches is expected to be between 1.5′ to 3.5+ feet deep.
The overall snowpack depth varies across aspect. In general, West to North aspects have a deeper snowpack and East to South aspects have a shallower snowpack. There has been consistently more avalanche activity this season on the Southerly aspects where the snowpack is thinner, weaker, and therefore easier to trigger.
However, on Feb. 13th we saw a shift for avalanche activity. We observed 2 larger avalanches, 3+ ft deep, that were remotely triggered on west aspects. The sheer number of recent storms and loading events has shifted our concern from southerly aspects to all aspects for this problem. Triggering an avalanche on a leeward aspect carries a much higher consequence because of the depth of the weak layer.
If you get out please use safe travel protocol. In avalanche terrain, only expose one person to steep slopes at a time, choose safe zones out of the reach of avalanches for grouping up, always have a spotter in a safe location, everyone carries a beacon, shovel, and probe, and are prepared and practiced for companion rescue.
| 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 |
6″ to 9″ thick Storm Slabs will be likely to human trigger at mid and upper elevation, on all aspects, on slopes above 35°. Storm slabs may step down into the persistent slab, increasing the size and consequence of the avalanche.
Storm slabs typically last between a few hours and a few days. With additional snow forecasted throughout today and Wednesday, expect the avalanche hazard to linger and potentially increase within the next 24-48 hours.
