Bollettino valanghe

San Francisco Peaks / Kachina Peaks Wilderness

Kachina Peaks Avalanche Center
Vedi sulla mappa

Pericolo valanghe

Alta quota
2 · Moderato
Limite del bosco
2 · Moderato
Sotto il limite
1 · Debole
Open full map
Non aggiornato — questo bollettino è scaduto last year. Stai vedendo condizioni passate, non il bollettino in corso.

In sintesi

Although the avalanche danger has decreased, human-triggered avalanches remain possible on higher-elevation wind-loaded slopes and slopes with significant sun exposure. Backcountry travelers are urged to carefully assess snow conditions at mid and upper elevations (i.e., above ~10,500') before stepping out into steep terrain. Travelers should exercise heightened caution below steep loaded ridgelines, gullies, and convex rollovers and retreat if any instability is observed.

Coverage for backcountry skiing and boarding has improved, but rock or log strikes are inevitable on W, SW, S, and SE aspects at lower elevations.

Join us at our 20th Anniversary Celebration for an evening of food, beverage, and storytelling. 

Problemi valanghivi

  • Wind Slabs

    • Alta quota
    • Limite del bosco
    • Sotto il limite del bosco
    Probabilità
    Possible
    Dimensione
    1–2

    Generally, southwesterly winds transported snow on Friday and Friday night. Over the weekend, winds were moderate to high and primarily northwest; however, the specific direction often depended on local terrain features. Thus, stubborn wind slabs are expected to be on most aspects above treeline and leeward terrain features. On Saturday, shooting cracks were noted in areas with more consolidated slabs and a very small soft slab avalanche was triggered on a test slope. Based on several observations from Sunday, these instabilities seem to have decreased; however, forecasted southwest winds will continue transporting any available snow, creating new windslabs at higher elevations, which could be sensitive.

    Backcountry travelers should carefully assess or avoid loaded starting zones, wind drifts, mounds of snow, pillowed areas, and cornices while traveling in avalanche terrain. One way to assess these instabilities is through small and inconsequential test slopes, which can be invaluable in assessing the reactivity of wind slabs on specific aspects and around terrain features.

    Moreover, it is imperative for travelers to consistently employ appropriate travel techniques aimed at minimizing risks to themselves, their party, and other individuals in the vicinity. These measures include only exposing one person at a time to avalanche terrain while skiing and while egressing. Likewise, skin tracks and egress routes should aim to utilize local terrain features to minimize the likelihood of triggering an avalanche.

    Crown line from a very small soft slab avalanche. Crown was ~15" high and 15 feet wide that was triggered on Saturday.

    Photo: Tanner Porter

  • Loose Wet

    • Alta quota
    • Limite del bosco
    • Sotto il limite del bosco
    Probabilità
    Possible
    Dimensione
    1–2

    Monday is expected to have similar high temperatures to Sunday, making small wet loose avalanches possible in the afternoon, especially on slopes with high sun exposure and lower elevations with warmer temperatures. On Sunday, several solar aspects and lower elevation slopes were beginning to show tell-tale signs of increasing wet loose avalanche danger, including pinwheels. Generally, these wet loose avalanches start on the snowpack's surface as small point releases but will entrain more snow as they descend the slope.  On slopes that have wet and slushy snow, the risk of wet loose avalanches increases, especially near cliffs or rocks.

Avalanche Discussion

Due to the lack of propagation propensity of buried weak layers over the last week and the lack of definitive persistent slab avalanches, we have removed the persistent slab problem from the forecast. Although removed from the avalanche problems, backcountry travelers should still be aware of the persistent weak layer presence as significant changes in weather, such as additional snow or warming, or large wind slab avalanches could increase the propagation propensity, causing large (i.e., D2-D3) destructive avalanches. The layers of concern include basal facets (i.e., depth hoar) at the base of the snowpack and faceted layers (i.e., buried near-surface facets) throughout the snowpack. The buried near-surface facets can be identified by small (i.e., a few centimeters) layers of less cohesive and lower-density layers (i.e., four-finger hardness) often sandwiched between denser (i.e., pencil hardness) or ice layers.

Over the weekend, several small (<D2) soft slab avalanches were noted within the Humphreys Cirque and Dunnam Canyon, likely occurring on Friday and early Saturday morning. On Saturday, numerous shooting cracks were found across several aspects, and a very small soft slab avalanche was triggered on a steep rollover at ~11,600. On Sunday, there were no reports of these problems, signaling a decrease in the likelihood of triggering. However, expect continued winds to redistribute any snow available for transport, building more wind slab avalanches.

Recent observations indicate that the snowpack is characterized by poor to fair structure, moderate to high strength, and limited propagation propensity; however, as a rule, avalanche danger often increases when there are large changes to the snowpack and within the last 96 hours, 3-4" of snow water equivalent has been added to the existing snowpack and Monday is forecasted to be another warm day. 

Due to the increased uncertainty associated with minimal observations across the season, KPAC recommends careful snowpack assessment, conservative decision making, and avoiding wind-loaded slopes. Thoroughly assessing the snowpack of your entire route before committing to avalanche terrain will be key.

Lack of snow and warm weather for much of the season means plenty of rocks and logs just under the new snow, especially on W, SW, S, and SE aspects. Lower elevations and previously wind-scoured slopes above treeline will have numerous very thin spots. 

If you get out, please submit your observations or email us at [email protected]. 

KPAC has documented evidence of several avalanches this season - Avalanche Database.  

Regioni coperte