Avalanche Forecast
Issued: Mar 23rd, 2020 4:00PM
The alpine rating is Wind Slabs.
, the treeline rating is , and the below treeline rating is Known problems includeNew snow is creating heightened avalanche conditions, especially in southern parts of the region.
Summary
Confidence
Moderate - Uncertainty is due to limitations in the field data.
Weather Forecast
Unsettled conditions with light flurries for the next few days.
MONDAY NIGHT: Cloudy with variable flurries bringing anywhere from 0 to 15 cm of new snow, light west wind, freezing level drops to valley bottom, alpine temperatures drop to -8 C.
TUESDAY: Cloud with isolated flurries and variable accumulations of 0 to 10 cm, light north wind, freezing level around 1000 m, alpine temperatures reach -4 C.
WEDNESDAY: Mix of sun and cloud, light northwest wind, freezing level around 1000 m, alpine temperatures reach -4 C.
THURSDAY: Increasing cloud in the afternoon, moderate southwest wind, freezing level around 1000 m, alpine temperatures reach -4 C.
Avalanche Summary
No recent avalanches have been reported, but mountain travel and field observations have been very limited over the past few days. Last week there were many wet loose avalanches and some large glide slabs, but cooler weather and new snow has probably made new wind slabs the main concern this week.
Snowpack Summary
Current unsettled weather will continue to give localized accumulations of new snow on Tuesday, with the most probable accumulations around the southern part of the region (i.e. Cascades). Snowfall amounts as of Monday afternoon are 2-15 cm, and these amounts could double by Tuesday afternoon. The new snow is burying moist and crusty snow, as well as potentially some small surface hoar on shaded slopes at lower elevations. Overall, there is some uncertainty about how well the new snow will bond to these interfaces.
Northern parts of the region (e.g.. Duffey/Hurley/Gold Bridge) have had a deep instability lingering at the base of the snowpack for most of the season. While this layer has gained strength over the past month (the last reported avalanche was on Feb 17), it is still worth considering when assessing shallow, rocky slopes in this part of the region.
Terrain and Travel
- Watch for newly formed and reactive wind slabs as you transition into wind affected terrain.
- Closely monitor how the new snow is bonding to the old surface.
Problems
Wind Slabs
Scattered flurries could form unstable slabs in localized areas. Slab formation is most likely in the southern part of the region, which has received the most snow so far and is also expecting the most on Tuesday. There is uncertainty about how well these slabs will bond to underlying interfaces.
Aspects: North, North East, East, South East, North West.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Valid until: Mar 24th, 2020 4:00PM