Hatcher Pass Avalanche Forecast
|
![]() ![]() |
Today’s avalanche problems will be persistent slab and dry loose. Human triggered persistent slab and dry loose avalanches will be possible on all aspects at mid to upper elevations. Natural avalanches are unlikely. Stiff hard snow on top of weak sugary facets is a sign that the persistent slab problem is present.
Remote triggering a persistent slab avalanche is possible. Choose safe zones carefully and beware of steep terrain that is above you.
At lower elevations, persistent slab problems are unlikely and small dry loose avalanches are possible.
A few new inches of new snow has improved coverage but the snowpack is still thin and shallow in many areas. Getting caught in any avalanche will have high consequences, due to the potential of carrying a person through thinly buried rocks and other hazards.
Riding conditions have improved slightly in isolated 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 |
Human triggered persistent slab avalanches are possible at mid to upper elevations on all aspects, in terrain 30° or steeper. Natural avalanches are unlikely. Expect these avalanches to be large enough to bury, injure or kill a person. Persistent slab avalanches will be unlikely at lower elevations. Remote triggered avalanches will be possible.
Instability tests continue to be reactive in areas where a stiff hard slab can be found. Reports of whumping and shooting cracks earlier in the week are a great reminder that this problem has not gone away.
This type of avalanche problem is difficult to predict. It may allow you to travel multiple times on a slope before triggering an avalanche. Tracks on a slope are not an indicator of stability. A single snow pit with stable results will not necessarily be representative of the slope you are testing.
Hard slabs will allow you to travel out onto a slope before failing above you making escape difficult to impossible. Avoid cross loaded gullies and slopes with old stiff snow.
Two weak sugary layers of facets still exist in the snowpack. One layer of basal facets is found at or near the ground, and is buried under 1-3’ of snow. The other layer of rounding facets is closer to the surface and is buried 12”-18” from the surface.
Any hard dense snow sitting on top of weak sugary facets, should be given extra caution. To identify these conditions use hand pits, pole tests and instability tests. Shooting cracks, collapsing and whumping will all be red flags for this problem.
To increase your margin of safety for this avalanche problem, use disciplined safe travel protocol and avoid slopes with terrain traps. Use adequate spacing when traveling uphill, ride one at a time down slopes, spot your partners, and use safe zones that are out of harm’s way.
Avoid any slope that is above a terrain trap. Getting caught in an avalanche above a creek, gullie or slope with an abrupt transition will increase your burial depth. Terrain traps increase your burial depth and make a successful rescue more challenging.
2-3mm basal facets
Snow pit from marmot 12/16
Coverage is slowly improving but hazards sit just below the surface
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 |
Human triggered dry loose avalanches are possible, and natural avalanches are unlikely. This avalanche problem will be found at all elevations and on all aspects and in terrain 40° or steeper. 1-2” of newer, low density snow will be easy to trigger, and may entrain deeper, weak snow.
Loose dry avalanches will be small in size, but may be able to catch, carry, and sweep a person into more consequential hazards, such as rocks or over cliffs.
Columns and stelar dendrites. Yesterdays storm snow, todays dry loose problem
New snow totals 12/13-17
Independence mine: 1-2″
Frostbite ridge: 2-3″
This week the weather has been relatively stable. On Sunday frostbite weather station reported temps above freezing for most of the day. Independence Mine was a little bit cooler but still made it above freezing for a few hours. On monday temperatures began to drop into the lower 20s at all the weather stations and have remained cool throughout the week. Calm east to south winds have spared our snowpack and made for pleasant riding conditions. On Wednesday 1-2″ of snow fell just barely hiding old tracks, rocks, and other hazards.
NWS Rec Forecast here.
NWS point forecast here.
State Parks Snow Report and Motorized Access information here.
Frostbite
|
Temp
|
RH
|
Spd
|
Gust
|
Dir
|
|
|
|
SWE
|
SnoHt
|
|
---|---|---|---|---|---|---|---|---|---|---|---|
Min | 13 | 49 | 0 | 0 | N | 5.1 | 21 | ||||
Max | 36 | 102 | 7.2 | 16.9 | NNW | 5.2 | 24 | ||||
Average | 26.7 | 77.4 | 2.6 | 6 | – | 5.1 | 21.6 |
Independence Mine
|
Temp
|
RH
|
Spd
|
Gust
|
Dir
|
|
|
|
SWE
|
SnoHt
|
|
---|---|---|---|---|---|---|---|---|---|---|---|
Min | 10 | 41 | 0 | 0 | N | 5 | 21 | ||||
Max | 34 | 95 | 6.7 | 13.5 | N | 5.5 | 23 | ||||
Average | 23.4 | 73.4 | 2.7 | 5.3 | – | 5.1 | 22 |
Marmot
|
Temp
|
RH
|
Spd
|
Gust
|
Dir
|
---|---|---|---|---|---|
Min | 8.5 | 38 | 0 | 2 | N |
Max | 30.3 | 100 | 14 | 27 | N |
Average | 21.1 | 81.7 | 4 | 8.1 | ENE |