Avalanche Forecast
Issued: Feb 23rd, 2015 8:37AM
The alpine rating is Wind Slabs.
, the treeline rating is , and the below treeline rating is Known problems includeSummary
Confidence
Fair - Wind speed and direction is uncertain on Tuesday
Weather Forecast
The current ridge of high pressure will persist for Tuesday and Wednesday bringing a mix of sun and cloud to the forecast region. By Wednesday evening a pacific frontal system will make its way into the Columbia Mountains, although only overcast skies and trace amounts of snow are expected on Thursday. Ridge top winds are forecast to be strong from the northwest on Tuesday, and then become light on Wednesday and Thursday. Freezing levels should hover around 1500m on Tuesday, and then drop to near valley bottom on Wednesday and Thursday.
Avalanche Summary
Avalanche activity has generally tapered off throughout the past week, although there was some reported human-triggered wind slab activity to size 1 at higher elevations over the last few days. The wind slabs formed in response to northwest winds redistributing recent snow accumulations. Current wind slabs may remain sensitive to human triggering while forecast strong northwest winds may promote new wind slab activity on south-facing slopes.
Snowpack Summary
Light amounts of recent snowfall (5-20 cm) cover the previous variable snow surface of surface hoar, crusts, dry facetted snow, or wind affected snow depending on aspect and elevation. The "Valentine's Day" crust is just below the surface and is now strong and thick in most places. New wind slabs may have formed in lee terrain from recent W-NW winds, and cornices remain large and weak. The late-Jan crust/surface hoar layer (up to 100 cm deep) and the mid-January surface hoar (80-120 cm deep) are generally dormant, and chances of triggering these weaknesses have decreased. However, triggering may be possible with a large input such as cornice fall, or an avalanche stepping down, especially on sun drenched slopes.
Problems
Wind Slabs
Aspects: North, North East, East.
Elevations: Alpine.
Likelihood
Expected Size
Valid until: Feb 24th, 2015 2:00PM