Lawinenlagebericht

Continental

Valdez Avalanche Center
Auf der Karte ansehen

Lawinengefahr

Mon
Hochgebirge
3 · Erheblich
Waldgrenze
3 · Erheblich
Unterhalb
3 · Erheblich
Open full map
Veraltet — dieser Lagebericht ist 3 years ago abgelaufen. Du siehst vergangene Verhältnisse, nicht den aktuellen Bericht.

Kernpunkte

Sunday afternoon update (3:20 PM):  The avalanche hazard is moving to high this evening as heavy snowfall is expected to continue overnight with increasing temperatures that will create widespread areas of unstable snow.  

The avalanche hazard is Considerable at all elevations.  Dangerous avalanche conditions exist, human triggered avalanches are likely up to 2 feet in depth. Natural avalanches are possible.  Cautious route finding and conservative decision making will be necessary for safe travel in avalanche terrain today.

 

 

Lawinenprobleme

  • Storm Slabs

    • Hochgebirge
    • Waldgrenze
    • Unterhalb der Waldgrenze
    Wahrscheinlichkeit
    Likely
    Größe
    1–2.5

    Heavy snowfall began overnight with 11 additional inches in Valdez as of 6 am and 6-8 inches reported by DOT on Thompson Pass and a similar amount at 46 mile.  This brings storm totals to 6-18 inches so far with the higher amounts towards the coast.  Heavy snow is forecasted to continue today with 2 feet of additional snowfall possible through Monday.  Temperatures are expected to warm through the day  and may drive the snow line to 2000' by this evening.  Even if snow does not turn to rain an increase in temperatures will create heavier snowfall that will make storm slabs top heavy and more sensitive to human triggers and increase the likelihood of natural avalanche activity.

    On 1/27, 6 inches of uncohesive snow (no slab) was found on a very hard low friction bed surface.  New snow is expected to become cohesive (slab) as temperatures warm during the day and snowfall becomes denser.  As new snow forms a slab, human triggered avalanches are expected to become likely up to 2 feet in depth in terrain steeper than 30°.  New snow is expected to bond poorly with the hard wind board that was buried yesterday.  Natural avalanches will become possible as temperatures warm across the area and a slab forms.  

    Our upper snowpack is undergoing a major change,  as this change is occuring expect to find elevated avalanche hazard.  Watch for signs of instability such as shooting cracks, collapsing and avalanche activity and avoid slopes steeper than 30° where they are present.  Avoid exposure to terrain traps today and pay attention to not just the terrain that you are on, but also what is above you.  

     

  • Glide Cracks

    • Alle Höhenlagen
    Wahrscheinlichkeit
    Unlikely
    Größe
    2.5–3

     Glide avalanches are a strange beast that act differntly than other avalanche problems.  Full depth failure occurs independent of snowpack stability.  Or in other words, they can release even when a stable snowpack is in place.

    Since it is not possible to time their sensitivity the only way to mitigate this hazard is by avoidance.  First identify where glide cracks exist and avoid spending time beneath them.  Glide cracks are easy to identify.  They look like crevasses, but exist in non glaciated terrain.

    These do not produce small avalanches,  but rather failure will include the entire snowpack.  

    Glide release on Town mountain

    Photo: Rich Lofton

Avalanche Discussion

A major change in the upper snowpack is occurring today with heavy snowfall accumulations coupled with rising temperatures.  New snow is falling on a low friction bed surface that will make bonding intially difficult, increasing the odds of human triggered and natural avalanches especially as temperatures warm and a cohesive slab is formed.  Avalanches that do occur are expected to run fast due to the hard bed surface that is in place.

Patience is recommended today as new snow will need time to bond with previously wind damaged surfaces.  Cautious route finding and conservative decision making will be critical for safe trave in avalanche terrain today.

Glide cracks have been observed in all three forecast zones.  Avoid travelling beneath these as full depth avalanches can release unexpectedly.

Valdez season snowfall: 171 inches

Valdez January snowfall: 27 inches

Valdez height of snowpack: 52 inches

Thompson Pass snowfall data is currently unavailable

46 mile height of snowpack: 66 inches

Abgedeckte Regionen