Hatcher Pass
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The Bottom Line
There is a MODERATE avalanche danger on all aspects and elevations. 10 to 17 inches of new snow over the last 4 days has resulted in relatively few natural and human triggered avalanches in steep terrain and/or on firm bed surface layers that contain weak snow grains. Slopes over 40º in steepness should be approached with caution due to the potential for DRY LOOSE avalanches. It may be possible to trigger PERSISTENT SLAB avalanches on specific windward locations in the upper elevations.
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| Fri, December 22nd, 2023 |
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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. |
Two human triggered avalanches were reported here. Hatch Peak 12-16 & Gold Mint Trailhead 12-17
Several loose dry and shallow slab avalanches were observed on Wednesday. No human triggered avalanches were observed or reported on Wednesday.
12-20 Persistent Slab Avalanches near Martin Mine on East-Southwest Aspects 4400ft
credit: Elias Neuffer
12-20 Persistent Slab Avalanches in Martin Mine on East-Southwest Aspects 4400ft
12-20 Shallow Snowpack on Windward Southeast Aspect 4068 Peak at 3500ft
| 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 |
During the past 4 days Hatcher Pass has accumulated 10 to 17 inches of new low density snow. Good visibility revealed few natural dry loose avalanches. These were found in terrain steeper than 40º on numerous different aspects in the mid and upper elevations. One human triggered avalanche within the new loose snow was reported yesterday, but sluffs were small and manageable. Confining terrain such as gullies, or where abrupt changes in slope angle occur are likely places to trigger this unconsolidated snow. Expect to find this avalanche problem on all aspects and elevations.
12-20 Loose Dry Avalanches on Marmot Peak Southwest Aspect 4200ft
| 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 the morning overcast burned off on 12/20 and good light hit the slopes, we were able to see the remnants of surprisingly few and widely connected crowns from avalanches within the recently deposited snow. These wide propagating yet thin, 5 to 10 inches thick slabs were observed in places where previously strong winds had scoured the snowpack to firm old crusts or bed surfaces or nearly bare ground. The presence of Facets, some near or on the surface of these firm layers likely contributed to the array of avalanches seen today and over the weekend on some mid elevation slopes.
The sliding surfaces for yesterday’s recent slab avalanches are located specifically on windward aspects, and mostly confined to the upper elevations. Prevailing winds from the east/southeast previously scalloped away the soft snow leaving behind firm surface layers that will readily shed new snow. Avoiding slopes 30 degrees and steeper that face east to southwest in the upper elevations, especially those with a firm subsurface layer will give you a better margin for safety.
Although the presence of persistent grains has not been found nor reactive everywhere on the slopes does not mean that they aren’t lingering in the snowpack. Cold and dry conditions can promote the growth and sensitivity of these weak grains allowing them to remain dormant and stubborn for a duration of time and then reemerge later. Shallow snowpack areas are the best place to find and trigger persistent slab avalanches which may be large in some isolated locations.
12-20 Persistent Slab Avalanches on Eldorado Bowl Southeast Aspect at 4200ft
credit: Elias Neuffer
