Avalanche Forecast
Issued: Mar 23rd, 2016 8:26AM
The alpine rating is Persistent Slabs, Deep Persistent Slabs and Cornices.
, the treeline rating is , and the below treeline rating is Known problems includeSummary
Confidence
Moderate - Timing or intensity of solar radiation is uncertain
Weather Forecast
The Jet stream is to the north of the Rockies at moment. Tonight the winds are forecast to be strong out of the west through the evening. Winds will taper in the am and the freezing levels are set for 1600 meters with trace precipitation in the next 24 hrs.
Avalanche Summary
Yesterday Banff Visitor Safety Forecasting team did avalanche control on the Bourgeau 4 path and got a size 2.5 slab avalanche result. Temperatures were cool this morning but freeze levels have been in the 1800-2000 meter range so activity coincides with the sun and warming air in the afternoon. Pay attention to the daytime heating and any new storm loads over the next while.
Snowpack Summary
We continue to see evidence that our snowpack is not yet a spring snowpack and still very much a winter snowpack. The upper snowpack is complex with 4-5 melt form crusts that vary in depth from just below the surface and up to 80cm deep. These melt form crusts, particularly the Feb11th crust are highly suspicious as we saw many large size 2.5-3.0 avalanches out of steep hanging alpine walls. some initiated by cornice failures and others failing with heat (solar or ambient air temperatures approaching zero degrees). The second and biggest concern for us at the moment is the Jan 6th interface (facets) buried anywhere from 60-110cm in the snowpack - a legitimate deep Persistent Weak Layer. This is the layer that is associated with the very long drought we had that started shortly after Dec 20th and extended into the 2nd week of January before another storm buried these facets. This layer is showing highly variable results in snowpack tests and high degree of variability in its distribution. Essentially we have a very low degree of confidence as forecasters in the snowpack.
Problems
Persistent Slabs
Aspects: All aspects.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Deep Persistent Slabs
Aspects: All aspects.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Cornices
Aspects: North, North East, East, South East.
Elevations: Alpine.
Likelihood
Expected Size
Valid until: Mar 24th, 2016 2:00PM