Avalanche Forecast
Issued: Mar 18th, 2013 11:05AM
The alpine rating is Wind Slabs, Persistent Slabs and Loose Wet.
, the treeline rating is , and the below treeline rating is Known problems includeSummary
Confidence
Fair - Forecast snowfall amounts are uncertain on Wednesday
Weather Forecast
Tuesday: Mix of sun and cloud / Light to moderate southwest winds / Freezing level at 1200mWednesday: Moderate to heavy snowfall /Â Strong to extreme southwest winds / Freezing level at 1500mThursday: Light snowfall / Light to moderate west winds / Freezing level at 900m
Avalanche Summary
A widespread slab avalanche avalanche cycle to size 2 took place on Sunday. The activity occurred in response to new snow and variable winds at all elevations. One notable occurrence was a size 3 slab avalanche which took place in the southeast corner of the region. The avalanche occurred on an east-northeast aspect at 2500m and was likely triggered by rapid loading from strong northwest winds. Observations were limited, but its size may suggest that a persistent weakness was the failure plane.
Snowpack Summary
Light to locally heavy amounts of new snow fell over the weekend and have have been distributed by northerly winds into deeper windslabs in lee terrain. These recent accumulations overlie a thick rain crust which is reported to extend up to 2000m. About 1m below the surface is a layer surface hoar or a sun crust buried on March 10th. Avalanche activity has become less likely at this interface; however, isolated natural activity and remote triggering is still occurring in some areas. At lower elevations where last week's heavy rain saturated the snowpack, subsequent cooling has formed crusts and has dramatically strengthened the snow.Weaknesses deeper in the snowpack have become unlikely to trigger.Widespread cornice development has also taken place, and cornices are reported to be very large and weak.
Problems
Wind Slabs
Aspects: North, North East, East, South East, South, South West.
Elevations: All elevations.
Likelihood
Expected Size
Persistent Slabs
Aspects: All aspects.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Loose Wet
Aspects: North, North East, East.
Elevations: All elevations.
Likelihood
Expected Size
Valid until: Mar 19th, 2013 2:00PM