Avalanche Forecast
Issued: Jan 7th, 2014 8:32AM
The alpine rating is Wind Slabs and Persistent Slabs.
, the treeline rating is , and the below treeline rating is Known problems includeSummary
Confidence
Good
Weather Forecast
Tonight and Wednesday: A weak system will pass through tonight and ease Wednesday morning. Expect light precipitation, Westerly winds switching from the SW with freezing levels at the surface. Thursday: As another system dives South into Washington Wednesday night, the region could see very light to light amount of precipitation early Thursday and then easing off during the day. Winds should be from the W with freezing levels at the surface.Friday: The zonal flow is allowing another system to pass through but quantities are unsure as models do not agree on track and timing of the system. Freezing levels are forecasted to rise.
Avalanche Summary
Windslabs were triggered by a vehicle and by explosive control in the Eastern part of the region on an E facing aspect slopes. These avalanches were up to 1.5 in size and would have slid on older faceted surface or on low density new snow. A detailed incident report about the Corbin area near miss is available here.
Snowpack Summary
There are pockets of windslab on lee side of SE and SW winds below ridgetop in the alpine. The storm slab is settling but is still sensitive to human trigger, especially where a weak faceted snowpack is underlying that top fresh layer. The facet/crust layer down 80-100 cm at treeline and below treeline and the depth hoar layer in the alpine seems quite reactive on E aspects. Multiple recent natural and human triggered avalanches on this aspect is a good sign of this instability. When tested and observed, the surface hoar layer down 70 cm is showing signs of healing (grains are rounding and snowpack test are not as planar as they used to be). The South Rockies field team has posted a new blog with some good info and pictures about the recent avalanche incident and about current conditions. Click here to read it.
Problems
Wind Slabs
Aspects: North, North East, East, South East, South, South West.
Elevations: Alpine.
Likelihood
Expected Size
Persistent Slabs
Aspects: All aspects.
Elevations: All elevations.
Likelihood
Expected Size
Valid until: Jan 8th, 2014 2:00PM