Hatcher Pass

With over 72 hours of moderate to strong winds and temperatures reaching into the 40°s, surface snow conditions have dramatically changed from last week. Loose dry snow has been transported around the mountains or is actively melting and becoming unconsolidated. Natural avalanches have occurred in multiple different locations and some of them have been large enough to bury a human.

~Dylan’s Molar east of Rae Wallace a large natural D2+ wind slab avalanche with multiple paths converging with debris 4-5’ deep north & northwest aspects at 4200’ on 2/13

~Hatch Peak had two large natural D2 avalanches occur on the north/northwest aspects at around 4100 feet on 2/13

~Marmot “Death Gully” natural D2 avalanche in cross-loaded terrain feature north/northeast aspect which filled in some of that terrain trap on 2/12

~Marmot “Fern Path” natural D2.5 avalanche partially crossed groomed cross country ski corridor on 2/13

~Marmot 1 & Archangel 1 natural D2 avalanches with debris in drainages on 2/13

~Martin Mine natural D2 avalanche on a north/northeast aspect and sympathetically released an avalanche on the opposing south side of the gully both exposing the ground on 2/12

~Frostbite natural D2 avalanche on prominent northwest face above Skeetawk on 2/13

Large Natural Avalanches near Dylan’s Molar East of Rae Wallace Northwest Aspect at 4200 feet 2/14/24

Natural Wind Slab Avalanche on Frostbite Northwest Aspect at 3500 feet 2/14/24

2/14 Natural Archangel 1 path from wind slab and wet loose debris SW to SE aspects 3200-4000′. Photo: Tim Escher

Two Natural Avalanches on Hatch Peak North Aspect at 4000 feet 2/14/24

On Monday 2/12 moderate to strong south & southeast winds began to transport any available snow creating firm slabs up to 3 feet thick on leeward aspects. Most of these wind slabs can be found on slopes facing southwest through northeast. It will be possible to trigger these slabs in the mid and upper elevations on slopes steeper than 35°. Slabs are thinner and less pronounced at low elevation. Since Monday the winds have been consistently moderate to strong with extreme gusts of 68mph recorded on Marmot Peak at 4500 feet.    

Wind transported snow has the capability of loading slopes ten times faster than any storm can produce. Rapidly loading snow is a major RED FLAG and has contributed to this cycle with multiple natural avalanches occurring on a variety of different aspects. Natural wind slab avalanches up to 3 feet thick have been observed on leeward slopes and cross-loaded terrain. Some of these avalanches have propagated below ridgelines and cornices, exposing the ground. A couple of these avalanches converged in drainages and sympathetically released avalanches on adjacent slopes, making the debris in terrain traps that much deeper.

The 72 hour duration and intensity of the wind has changed the enjoyable riding conditions, leaving in its wake a lunar landscape. Raised ski tracks (anti-tracks), sastrugii (wind sculpted snow), and older avalanche debris has emerged from the snowpack as the unconsolidated snow is being eroded away by fierce winds. Below these slabs a mixture of recent soft snow or older faceted weak snow is unable to support the weight of the overlying wind slabs, helping contribute to the problem. Thickness, hardness and sensitivity of these wind slabs is highly variable and changes from one step to the next. 

With the current scenario it can be difficult to give accurate travel advice. Shooting cracks and audible collapses as you approach these slabs are indicators of the problem. No one enjoys riding pencil hard surfaces riddled with anti-tracks or watching your tips submarine below a breakable crust. Wind protected areas may be difficult to find in the Mid and Upper elevations. As the sensitivity of these slabs decreases with time and diminishing winds throughout today, sticking to simple and lower consequence terrain is the best approach. Smooth textureless slopes steeper than 35° will be more likely places to trigger an avalanche. We recommend avoiding steep wind-loaded slopes and terrain traps where the risk of and consequence of triggering an avalanche is more serious.

With the recent warm temperatures reaching mid 40°s Fahrenheit at 2700 feet, and lack of an overnight refreeze for 3 evenings in a row below 2700 feet, surface melting of the snow has occurred. Last night temperatures did not get below freezing up to 4500 feet at our Marmot weather station. Melting is most pronounced in the Mid to Lower elevations and is especially apparent on slopes that face south, into the sun. Yesterday at Independence Mine the temperature peaked at 41°F, although intermittent strong winds kept snow surfaces mostly dry. Rollerballs and easily formed snowballs are indicators that loose wet avalanches are possible. If temperatures continue to remain warm overnight without a drop below freezing, expect this problem to increase.

Low elevation may be the best riding conditions but expect temperature to dictate whether the surface is squishy and moist or its crusty and refrozen. The projected weather forecast does show somewhat of a decrease in temperature for the mid and upper elevations but temperatures will hover near freezing below 2500 feet.