Ogden

Lawinenprobleme

• 

  Wind Slabs

  N

  NE

  E

  SE

  S

  SW

  W

  NW

  • Hochgebirge
  • Waldgrenze
  • Unterhalb der Waldgrenze

  Wahrscheinlichkeit

  Likely

  Größe

  2

  Strong northwest winds are blowing at speeds of 25-30 mph, with gusts into the 30s this morning. The wind also blows across the mid-elevations, with gusts into the 20s and 30s at 8,000'. This wind will indeed create new shallow soft slabs of wind-drifted snow. The unfortunate news is we've seen wind over the past 48 hours from all directions and both shallow soft or old hard stiff wind slabs could be found (see pic below).

  If the snow is pillowy or rounded, you've likely found a new drift of wind-blown snow. If the snow is hard and hollow-sounding, you likely found a hard drift of wind-blown snow. I would expect wind-drifted snow on all aspects and elevations today.

  These drifts may break into the old snow surface, as many observers noted the old snow surface becoming loose and faceted from the past few days of clear and cold weather. Any wind-drifted snow avalanche can also step down to deeper, weaker layers on terrain facing west to north to east at the mid and upper elevations (see PWL below).

  Wind-affected terrain on the Ben Lomond Headwall (Dubovik photo)

• 

  Persistent Slabs

  N

  NE

  E

  SE

  S

  SW

  W

  NW

  • Hochgebirge
  • Waldgrenze
  • Unterhalb der Waldgrenze

  Wahrscheinlichkeit

  Likely

  Größe

  3

  The persistent weak layer (PWL) slowly continues to gain strength, and it is getting more difficult to trigger avalanches. The type of terrain you are more likely to trigger an avalanche failing on the PWL is thinner snowpack areas such as:

  • Mid-elevations (particularly between 7,000 - 8,000') where there is less snow.
  • Steep, rocky areas.
  • Slopes that have already avalanched (aka "repeater" slopes) and have partially filled in.

  If you trigger an avalanche in one of these thinner snowpack areas, it could propagate widely and up to 3 feet deep.