Avalanche Forecast
Issued: Mar 23rd, 2021 4:00PM
The alpine rating is , the treeline rating is , and the below treeline rating is Known problems include Wind Slabs and Cornices.
MBender,
Avalanche Canada
New snow and wind forecast for Tuesday night through Wednesday morning will form fresh wind slabs at upper elevations.
Summary
Confidence
Moderate - Forecast snowfall amounts are uncertain.
Weather Forecast
TUESDAY Night: Mainly cloudy with periods of snow, accumulation 5-15 cm, moderate west wind, treeline temperatures around -5 C, freezing level 800 m.
WEDNESDAY: Cloudy with flurries bringing 5-10 cm of new snow through the morning, moderate to strong southwest wind, treeline temperatures around -4 C, freezing level 1500 m.
THURSDAY: Mix of sun and cloud, light northwest wind, treeline temperatures around -3 C, freezing level 1600 m.
FRIDAY: Cloudy with sunny breaks, moderate northwest wind, treeline temperatures around -4 C, freezing level 1500 m.
Avalanche Summary
Reports on Monday showed several size 1.5-2 cornice releases with explosive control, as well as a few thin storm and wind slab avalanches to size 1.5 in the alpine. Loose wet and loose dry size 1 avalanches from steep terrain facing the sun were also reported in the afternoon.
Expect to see an increase in wind slab and possibly storm slab activity Wednesday with new snow and wind arriving Tuesday night.
Snowpack Summary
By Wednesday midday there may be anywhere from 10-20 cm of new snow from Tuesday night that has likely been redistributed by west and northwest winds. This adds to about 30+ cm accumulation from last weekend. All of the new snow sits above a widespread crust, with the exception of high north-facing terrain. Observations suggest the snow has bonded well to these old interfaces. There are currently no concerning weak layers in the snowpack, although a spotty early season facet layer deep in the snowpack could return as a problem later in the season.
Remember that cornices along ridgelines are large at this time of year and always have the possibility of failing naturally or from the weight of a human.
Terrain and Travel
- Be careful with wind loaded pockets, especially near ridge crests and roll-overs.
- Be alert to conditions that change throughout the day.
- Be alert to conditions that change with elevation and sun exposure.
- Pay attention to cornices and give them a wide berth when traveling on or below ridges.
Problems
Wind Slabs
New snow combined with wind Tuesday night and through Monday morning will build fresh reactive wind slabs in open terrain.
Aspects: North, North East, East, South East, South, North West.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Cornices
Cornices are large and looming along many ridgelines, and have likely grown with the recent snow and wind.
Aspects: North, North East, East, West, North West.
Elevations: Alpine.
Likelihood
Expected Size
Valid until: Mar 24th, 2021 4:00PM
