Hatcher Pass Avalanche Forecast
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The Bottom Line
The tides have turned! New snow and strong wind over the past 48 hours have shifted conditions from stale and stable to dynamic and elevated, increasing the avalanche danger.
The avalanche danger is CONSIDERABLE for STORM SLABS at mid and upper elevation, on all aspects, on slopes 35º and steeper where up to 8″ of new snow has accumulated over the past 48hrs.
A MODERATE hazard exists for WIND SLAB at upper elevation, on northerly aspects, on slopes 35º and steeper.
A MODERATE hazard exists for LOOSE DRY at all elevations, on all aspects, on slopes 40º and steeper in protected terrain.
Expect to find 3-4″ of graupel sitting on smooth crusts which may catch you off guard! This weak layer-bed surface combo can have big consequences producing larger avalanches with fast moving debris. Remotely triggering an avalanche will be possible today.
Safe travel protocol, cautious route finding and conservative decision making will be the difference between enjoying a beautiful day in the mountains or getting caught in an avalanche today.
A couple avalanches were reported or observed on Friday. Due to poor visibility most of the day we could not see anything and likely missed recent avalanches.
3/24 Remotely triggered storm slab WNW aspect 3600′ Death Gully of Marmot, reported at 6:30pm as the weather cleared. Avalanche was triggered from location where people are standing. Photo: Ranger Tiffany
3/24 A recent human triggered storm slab was triggered at 4600′ on a NW aspect on Friday. The crown was approximately 2″-6″ thick and failed on graupel sitting on a smooth crust.
3/24 Remotely triggered slab in Rae Wallace boot pack couloir with crown visible and wrapping under rocks approximately 50ft wide. 4200′ N aspect
3/24 A significant amount of graupel accumulated yesterday during the storm. Expect avalanches to fail in this weak layer today. Graupel will be sitting on smooth, firm bed surfaces.
| 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 |
After a near month-long drought, Hatcher Pass finally received new snow over the past 2 days which will shift todays paradigm considerably.
Storm slabs, 4 to 8 inches thick will be likely to human trigger on all aspects, at mid and upper elevation, on slopes 35º and steeper. Expect storm slabs to be soft yet cohesive, easy to trigger, and fast moving.
Up to 8″ of new snow combined with 3-4″ of graupel (think ball bearings) accumulated since 5am Wednesday. This weak layer/bed surface combo produced one natural avalanche observed on Friday evening and we expect that more occurred. In addition, one party remotely triggered a small storm slab Friday afternoon.
Expect storm slabs to fail within the graupel layer on top of smooth crusts which exist in most locations. Yesterdays storm slabs were reactive and soft, some barely cohesive enough to act as a slab.
3/24 Remotely triggered avalanche in the Death gully observed on Friday evening 3500′ WNW. This avalanche was triggered from the mid rib where folks are standing in the photo. Photo: Ranger Tiffany
To identify storm slabs use hand pits, small test slopes, and stability tests. Look for new snow that behaves like a cohesive slab. Cracking and collapsing will be red flags for this avalanche problem.
| 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 |
On Friday, south winds gusted 22-46mph for 12 hours at 4500′ transporting up to 8″ of new snow. 5 to 10″ thick wind slabs will be possible to human trigger on northerly aspects, NW to NE, at upper elevation near ridgelines and cross loaded features, on slopes steeper than 35º. Natural avalanches are unlikely.
Expect new wind slabs to be sitting on graupel on smooth firm crust bed surfaces.
In isolated locations, it may be possible for wind slabs to fail deeper in the snowpack, up to 3 feet deep where old snow surfaces and 3/19 wind slabs will be buried by new snow.
HPAC webcam at the top of Marmot/Rae Wallace at 7:30pm Friday showing significant wind texture on the ridge.
To identify wind slabs look for hard snow sitting over weaker snow, smooth and rounded or lens shaped features. They may sound hollow or crack out from your ski tip as you travel across them. Shooting cracks or whumping are signs of instability and indicators of this avalanche problem.
| 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 |
Small to large loose dry avalanches (sluffs) will be possible to human trigger on all aspects at mid and upper elevations in protected locations on slopes 40º and steeper. For experienced skiers and riders, sluff management is an appropriate tool for mitigating this avalanche problem.
A few challenging factors for navigating this avalanche problem today are unique to yesterdays storm. 3-4″ or more of graupel accumulated and was buried and is sitting on smooth well preserved crusts (old wind slabs) near the surface, especially on leeward aspects. Graupel acts like ball bearings and will move very quickly with any sluff. In addition, many buried crusts are smooth, firm and barely edgeable which will make self arresting a challenge in the case of getting pulled off your feet in a sluff.
Getting caught up in a sluff in steep terrain may sweep you into terrain traps compounding the overall hazard.
It will be possible for sluffs to trigger storm slabs and vice versa.
On 3/23 IM@3550′ reported 3-4″ of new snow and 0.3″ SWE. On 3/24 IM received 5″ of new snow and 0.5″ SWE totaling approximately 8″ of new snow with 0.8″ SWE in the past 48 hours.
Frostbite@2700′ reported 8″ new snow with 0.8″ SWE in the past 48 hours.
On 3/24 South winds gusted 20-46mph for 10 hours @ 4500′.
NWS AVG Forecast here.
NWS point forecast here.
Marmot Weather Station here.
Independence Mine Snotel here.
Frostbite Bottom Snotel here.
State Parks Snow Report and Motorized Access information here.
XC trail grooming report for Mat-Su, Anchorage, and Kenai here.
