Hatcher Pass
|
Archives 
|
The Bottom Line
Today’s avalanche problems are Persistent Slab and Wind Slab.
Human triggered Persistent Slab avalanches are possible in isolated areas at upper elevations on southwest, west, northwest and north aspects. These avalanches will be small to large in size.
Human-triggered Wind Slabs are possible at upper elevations on west, northwest and north aspects. These avalanches will be small to large in size.
Natural avalanches are unlikely.
At mid and low elevations the avalanche danger will be low, where triggering an avalanche is unlikely.
The winds have greatly affected riding quality. On north aspects in protected areas, low density snow can still be found.
Special AnnouncementsCome join HPAC tonight, for a screening of the movie, BURIED, at the Beartooth fundraiser Thur March 24th. All new HPAC swag will be available for purchase.
HPAC will continue providing avalanche information till the end of our season April 16.
| |
|
 |
 |
 |
|
| 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. |
Two Human triggered slab avalanches were reported on March 22. Click here and here for more info.
A wide propagating human triggered slab avalanche in Lone Tree Gulch. This was triggered on March 22nd.
Loose wet avalanches were also observed on solar aspects.
Small wet loose on Arkose Ridge. Monday 3/21
| 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 |
Moderate to strong winds earlier in the week built slabs 4-18” thick on southwest, west, northwest and north aspects that are sitting on weak sugary facets, and in some locations on a crust. Many backcountry travelers have noted significant wind affected conditions in many locations this week.
In isolated areas at upper elevations on southwest, west, northwest and north aspects, human triggered avalanches are possible. These avalanches will be small to large in size. These avalanches will be found on slopes 30 degrees and steeper. Winds were more significant near Arkose Ridge; we believe slabs will be thicker in areas closer to Arkose Ridge. One person triggered a wide propagating D1.5 avalanche earlier this week near Lone Tree Gulch.
Wind affected snow is abundant near the Arkose Ridge Line.
To identify this avalanche problem use pole/probes, hand pits and formal stability tests. Look for hard dense snow sitting on top of weak sugary snow. Look for smooth wind drifted snow on or near ridge lines and cross-loaded gullies. Hollow sounding and drum like snow will be another sign that you’re like traveling over snow that has poor structure.
More wind affected snow above the Goldmint parking lot.
If you do head out into avalanche terrain use safe travel protocol. Spread out when ascending slopes, descend one at a time and regroup in areas out of harm’s way. Even a small avalanche can have severe consequences if you’re traveling above a terrain trap. Be mindful of what is below you.
| 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 |
Strong winds on 3/23 from the east and southeast transported snow for 5 hours, with gusts up to 38mph. These winds were able to create Wind Slabs 3-6” thick on west, northwest and north aspects at upper elevations. Human triggered avalanches are possible and natural avalanches are unlikely. These avalanches will be found on slopes 35 degrees and steeper, at and near ridge lines, and cross loaded gullies. There is some uncertainty in terms of slab thickness with minimal snow available to transport. After more sustained winds today it will be possible for wind slabs, to step down into the persistent slab in isolated locations.
To identify this avalanche problem use pole/probes and stability tests. Look for smooth, wind drifted snow. Strong winds are forecasted to continue in Hatcher Pass today. Look for signs of active wind loading, if you decided to head out into the mountains.
Flagging is a sign that wind is transporting snow. Monday 3/21
Some impressive anti tracks near Two Lake Valley.
There’s been minimal precipitation in Hatcher Pass over the last week. However there has been several wind events that have greatly affected riding quality.
Here’s a quick view of what’s been going on at Marmot weather station in terms of wind.
Wind speeds at Marmot Station 4500′ Mar 17-24
NWS AVG Forecast here.
NWS Rec Forecast here.
NWS point forecast here.
State Parks Snow Report and Motorized Access information here.
