Regions
Northwest Inland.
Warming is coming! This significant change will weaken the snowpack. Forecasting the timing of changes over the next several days is difficult. However, it's easy to see it's time to reign in your terrain choices and stay clear of overhead hazards.
Weather Forecast
A significant warm-up is happening and next week looks to be very warm with freezing level approaching 3000 m. Don't let overnight cooling in the valley fool you, very little overnight cooling at mountain elevations is expected.SATURDAY NIGHT: Overcast, dry, moderate southwest wind, little overnight cooling with freezing level staying around 1200 m. SUNDAY: Broken cloud cover, moderate southwest wind, freezing level around 2100 to 2400m with no overnight freeze.MONDAY: Sunshine, light south wind, freezing level as high as 3200m with no overnight freeze.TUESDAY: Sunshine, light southeast wind, continued high freezing level with no overnight freeze.
Avalanche Summary
There are few observers in the field this week but reports showed a natural avalanche cycle of storm and wind slabs up to size 2 early in the week and loose wet avalanches with afternoon warming.
Snowpack Summary
Up to 60 cm of upside down (higher density on top) storm snow has accumulated since Monday. This recent snow rests on previously wind affected surfaces, sun crusts (on solar aspects) and weak, sugary facets. The prolonged period of cold temperatures in February has had an overall effect of weakening the upper and mid-snowpack, as well as the basal snowpack in thinner areas.In the south of the region the lower snowpack is generally strong.
Problems
Storm Slabs
Storm Slab avalanches are the release of a cohesive layer (a slab) of new snow that breaks within new snow or on the old snow surface. Storm-slabs typically last between a few hours and few days (following snowfall). Storm-slabs that form over a persistent weak layer (surface hoar, depth hoar, or near-surface facets) may be termed Persistent Slabs or may develop into Persistent Slabs.
Persistent Slabs
Persistent Slab avalanches are the release of a cohesive layer of snow (a slab) in the middle to upper snowpack, when the bond to an underlying persistent weak layer breaks. Persistent layers include: surface hoar, depth hoar, near-surface facets, or faceted snow. Persistent weak layers can continue to produce avalanches for days, weeks or even months, making them especially dangerous and tricky. As additional snow and wind events build a thicker slab on top of the persistent weak layer, this avalanche problem may develop into a Deep Persistent Slab.