Avalanche Forecast
Issued: Feb 2nd, 2019 4:48PM
The alpine rating is Storm Slabs and Persistent Slabs.
, the treeline rating is , and the below treeline rating is Known problems include Natural avalanche activity has tapered off to some degree, but human triggered avalanches remain likely. Conservative terrain selection is recommended.
Summary
Confidence
Moderate -
Weather Forecast
SATURDAY NIGHT - Mainly cloudy with isolated flurries / southerly winds, 10-20 km/h / alpine low temperature near -12SUNDAY - Mainly cloudy with isolated flurries, 5-10 cm / southeast winds 10-25 km/h / alpine high temperature near -12MONDAY - A mix of sun and cloud / northeast winds 10 km/h / alpine high temperature near -16TUESDAY - Mainly sunny / northeast winds, 10-15 km/h / alpine high temperature near -12
Avalanche Summary
Avalanche activity continued on Saturday. Natural avalanches to size 3 and explosives triggered avalanches to size 2 were reported.On Friday a widespread natural avalanche cycle to size 3, as well as numerous human triggered avalanches to size 2 were reported. Some of these failed within the new storm snow, but many of them reportedly failed on a persistent weak layer that was buried in mid January.On Tuesday, in the neighboring Glacier National Park region, a size 3 avalanche was skier triggered on a steep southeast facing slope in the alpine. More details and photos here.
Snowpack Summary
20-70 cm of new snow has fallen in the region since Thursday. The highest amounts fell in the northeast corner of the region: east of the Columbia (Upper Arrow Lake) and north of Trout Lake, with a few exceptions. This new snow sits on wind slab, surface hoar (feathery crystals), facets (sugary snow) and a crust on sun-exposed slopes. A persistent weak layer that was buried in mid January is now buried 40-100cm. This layer consists primarily of surface hoar, however there is also a crust associated with it on sun-exposed slopes. This layer has been most reactive at treeline and below.
Problems
Storm Slabs
20-50 cm of new snow has fallen in the region since Thursday. It will take some time for this snow to bond to the underlying snow.
If triggered, storm slabs may step down to deeper layers and result in even larger avalanches.Avoid steep, unsupported slopes.
Aspects: All aspects.
Elevations: All elevations.
Likelihood
Expected Size
Persistent Slabs
45-100 cm of snow sits above a weak layer of surface hoar (feathery crystals) and crust. This layer will likely be reactive due to recent snowfall.
Any steep opening in the trees should be treated as suspect right now.
Aspects: All aspects.
Elevations: Treeline, Below Treeline.
Likelihood
Expected Size
Valid until: Feb 3rd, 2019 2:00PM