Avalanche Forecast
Issued: Feb 6th, 2023 4:00PM
The alpine rating is Storm Slabs.
, the treeline rating is , and the below treeline rating is Known problems includeNatural avalanches will be likely and human-triggered avalanches will be very likely due to accumulating storm snow.
Today will be a great day to dial it way back and keep a very conservative mindset.
Summary
Confidence
High
Avalanche Summary
Storm slabs have been reactive to explosives over the last three days ranging in size from one to two.
Size one avalanches triggered by skiers and snowboarders were reported to have occurred over the weekend.
On Thursday, there were reports of remote-triggered small slab avalanches. This is evidence of a poor bond with underlying surfaces which when loaded with the forecasted precipitation could result in a very active and large-scale avalanche cycle.
If you head to the backcountry please post your reports and photos to the Mountain Information Network, the information is very helpful to forecasters.
Snowpack Summary
By Tuesday morning there could be 80 to 90 cm of recent storm snow sitting over old wind-affected surfaces and hard crusts. Strong southwest winds are transporting this new and recent snow into deep pockets of wind slab on north and east-facing terrain at upper elevations. At lower elevations, recent precipitation may have fallen as rain.
A crust from mid-January can be found down 40 to 70 cm deep. A number of weak layers exist within the middle and lower snowpack, but the thick crusts sitting above them make triggering avalanches on these layers unlikely. The areas of concern in terms of triggering a deeper layer are shallow rocky areas where the snowpack varies from thick to thin.
Weather Summary
Monday Night
Cloudy, 20 to 35 cm accumulation with a mix of snow and rain below 1500 m, winds southwest 35 km/h gusting to 50, treeline temperatures -1 to -4 C.
Tuesday
Cloudy, 20 to 30 cm accumulation possibly more in some areas, winds southwest 50 km/h, treeline temperatures -3 C.
Wednesday
Cloudy with possible sunny breaks, trace accumulation, winds southwest 12 km/h, treeline temperatures -5 C.
Thursday
Cloudy, up to 10 cm accumulation, winds south 10 km/h, treeline temperatures -7 C.
More details can be found in the Mountain Weather Forecast.
Terrain and Travel Advice
- Storm slab size and sensitivity to triggering will likely increase through the day.
- As the storm slab problem gets trickier, the easy solution is to choose more conservative terrain.
- Be especially cautious as you transition into wind affected terrain.
- Dial back your terrain choices if you are seeing more than 20 cm of new snow.
Problems
Storm Slabs
Snow continues to accumulate over a variety of surfaces including stiff wind slabs and a faceting crust, which may take time to bond.
Strong southwesterly winds are transporting storm snow into deep pockets in lees.
At lower elevations precipitation may fall as wet snow or rain, watch for loose wet avalanche potential on steep slopes as the surface snow loses cohesion.
Aspects: All aspects.
Elevations: All elevations.
Likelihood
Expected Size
Valid until: Feb 7th, 2023 4:00PM