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The avalanche danger is MODERATE for dry loose avalanches (sluffs) at all elevations where triggering a sluff large enough to injure or bury a person is possible. Natural avalanches are unlikely.
Today will mark the 7th day in a row with below zero temperatures, more faceted powder than the day before, and a great day to get after big objectives with few avalanche concerns.
Sustained cold temperatures will taper Sunday as the next low pressure system arrives bringing 3 to 5 inches of new snow to the forecast area.
The HPAC Cabin Fever Reliever with The Jangle Bees and the drawing for our winter raffle are coming up next weekend, 2/10! Get your tickets to the party and raffle tickets today! All proceeds support HPAC and sustainable avalanche forecasting in Hatcher Pass.
Sun, February 4th, 2024 |
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. |
Few people have been out recreating this week most likely due to the extreme cold temperatures. Folks that have been braving the cold have been triggering mostly small to medium size dry loose avalanches (sluffs) in steep terrain 40º and steeper on all aspects above 3000 ft. A couple small shallow slab avalanches have been observed or reported this week in isolated locations and extreme terrain. These slabs have either triggered sluffs or sluffs have triggered small slabs a couple inches thick.
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 an insanely bitter cold week of weather with temperatures that even the old timers might whine about we have one predictable avalanche problem to contend with. The last recent storm on 1/28-29 deposited 5 to 8 inches of new low density snow followed by moderate to strong wind. The short duration of wind transported the low density snow surprisingly fast, creating variable conditions early in the week. However, over the several days cold temperatures have assisted wind slabs in deteriorating and faceting out, losing density and contributing to a dry loose avalanche problem this week.
The most likely locations for triggering a dry loose avalanche (aka sluff) today will be on steep convexities and rollovers in terrain 40º and steeper on all aspects and all elevations. They are most hazardous if you are caught and carried into a terrain trap such as a gully, cliff, or couloir. While most sluffs will be small, getting caught in steep terrain that funnels into any terrain trap has the potential to increase the size, risk and consequence of an avalanche.
On southerly aspects where dry unconsolidated snow sits on firm bed surfaces, sluffs will be more likely to trigger and result in a larger volume of debris. It will be possible to get caught and carried, injured, or tweek a knee in this terrain. As a result of the prolonged cold temperatures this week, sluffs are moving slowly and so are we. Sluff management and mitigating a sluff may be challenging today due to the slow nature of the snow and inability to get enough speed to ski or ride fast enough to avoid or outrun debris.
In isolated and extreme locations it will be possible to either trigger a sluff that propagates a small shallow slab avalanche or vice versa. Most likely locations are upper elevation, near ridgelines in areas previously exposed to the wind.