Avalanche Forecast

Moderate - Uncertainty is due to the fact that persistent slabs are particularly difficult to forecast. We have a good understanding of the snowpack structure and confidence in the weather forecast

A cooling trend lowers freezing levels this week and a weak front brings light snowfall on Monday.

SUNDAY NIGHT: Freezing levels fall to 1000m overnight. Moderate southwest winds. 

MONDAY: A mix of sun and cloud with flurries bringing up to 3cm over the day. Freezing levels reach 1100m, with light to moderate southwest winds and an alpine high of -4. 

TUESDAY: A mix of sun and cloud. Chance of flurries. Moderate westerly winds with an alpine high of -2. Freezing levels 1200m. 

WEDNESDAY: A mix of sun and cloud. Chance of flurries. Moderate to strong northwest winds, alpine high of -6 with 1000m freezing levels. 

On Saturday several natural persistent slabs were observed, triggered by tree bombs and cornice failures from the warmer temperatures. These failed on the late January surface hoar layer, on all aspects at treeline. A rider triggered a size 1.5 avalanche on this layer on Tuesday, in a steep south facing treeline feature.

Several natural and human triggered wind slab avalanches to size 2 have been reported this week, on north through east facing slopes.

The warming trend last week also produced skier triggered wet loose avalanches to size 1.5 in steep south facing terrain at treeline; and large naturally triggered cornice falls

Exposed terrain at alpine and treeline elevations hold dense wind effected surfaces with large cornices from westerly winds. Sheltered areas and lower elevations hold a widespread melt freeze crust.

The late January interface is buried 20-50cm deep, and consists of a melt-freeze crust at lower elevations and on solar aspects extending into the alpine. Surface hoar sits above the crust in sheltered areas at treeline and below.

Several surface hoar layers are now buried in the upper snowpack 40-120cm deep. The snowpack below is well consolidated, with the early-December crust/facet persistent weak layer buried 80-150 cm deep. It is currently considered dormant. We expect this layer to become active later this season, check out the forecaster blog for more information.

• Look for signs of instability: whumphing, hollow sounds, shooting cracks, and recent avalanches.
• Be aware of the potential for large avalanches due to the presence of buried persistent weak layers.
• Be alert to conditions that change with aspect and elevation.