Eastside Region

Lawinenprobleme

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  Wind Slabs

  N

  NE

  E

  SE

  S

  SW

  W

  NW

  • Hochgebirge
  • Waldgrenze
  • Unterhalb der Waldgrenze

  Wahrscheinlichkeit

  Very Likely

  Größe

  2–3

  Significant wind slab will be found on W-NW-N-NE-E-SE Aspects especially at the High and tree-line elevations today. With ~20” of new snow overnight at 9000ft (Mammoth area) and significant totals projected during the day, there undoubtedly will be widespread, sensitive, wind slab  in the mountains. Strong to Extreme Southerly winds have been blowing all night and are projected to continue throughout the day for the highest elevations, loading slopes with transportable fresh snowfall.  Areas adjacent to ridgeline, cliff bands, rock outcroppings, and roll overs are all terrain features where wind slab will be exacerbated. Travel within or underneath avalanche terrain today is not recommended. Slides could be large to very large and run long distances. Pay attention, and know what is above you especially with minimal visibility to reduce exposure to avalanche hazard.

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  Storm Slabs

  N

  NE

  E

  SE

  S

  SW

  W

  NW

  • Hochgebirge
  • Waldgrenze
  • Unterhalb der Waldgrenze

  Wahrscheinlichkeit

  Very Likely

  Größe

  1–3

  With close to 20” of snow falling overnight, (focused on the Mammoth area), and potentially a lot more snow on tap for today, be aware of new soft storm slab throughout the zone.  Consider ALL ASPECTS at ALL ELEVATIONS for this problem as snowfall is expected to be rapid and intense. Travel in avalanche terrain is not recommended as this rapid snowfall will be sensitive and reactive to human trigger, especially in steeper 35+ degree terrain. Shooting cracks, audible whumpfing, and fresh fat looking slopes are signs of building storm slab.  Overnight snowfall was less, but not insignificant in other parts of the forecast zone ranging from 6-9” in sheltered mid-elevation weather plots from Virginia Lakes down to Big Pine.

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  Persistent Slabs

  N

  NE

  E

  SE

  S

  SW

  W

  NW

  • Hochgebirge
  • Waldgrenze
  • Unterhalb der Waldgrenze

  Wahrscheinlichkeit

  Possible

  Größe

  2–3

  The intense snowfall, extreme winds, and rapid loading will test the weak old snow that resides at the base of the snowpack throughout the forecast zone. This moisture laden storm with heavy water content will add a lot of weight to underlying weak snow and avalanches could “step down” into old weak snow layers creating large and destructive slides. Areas of most concern are from around 9200ft to 10000ft in sheltered Northerly-Easterly terrain within trees. Weak old snow does exist widely and the condition should be considered on most aspects W-NW-N-NE-E-SE. Although we have found strengthening conditions at the interface between the old autumnal snow and last weeks big storm, this new additional load has the possibility of providing the trigger in exceptionally weak spots such as steep boulder strewn terrain with lots of cavities or convex roll overs.