Tonight will bring a spike in precip, alpine winds and temperature. With that spike, a rapid deterioration in avalanche conditions can be expected. Give alpine features lots of respect tomorrow. MM
Confidence
Fair - Intensity of incoming weather is uncertain on Saturday
Weather Forecast
The spring like conditions will continue for the next 24 hours. The precip associated with the Pineapple Express will peak at midnight tonight. We can expect up to 20 cms near the divide. Winds are now forecasted to be slightly less than they were, BUT this puts them in a range that is even more conducive to wind slab development.
Avalanche Summary
No new avalanche observations today due to poor visibility.
Snowpack Summary
Light precip today has left us with 10cm at TL and counting. This new snow has come in warmer than usual. Expect to see a dramatic change in snow density as you climb higher. ALP elevations will have dry snow that is more than willing to be transported by the wind. Expect storm slabs. TL has the most variable snow density. Transport will increase in proportion to the wind. BTL snow is heavy and sticky. It will bond quickly, however "upside down" conditions can be expected.
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.
Wind Slabs
Wind Slab avalanches are the release of a cohesive layer of snow (a slab) formed by the wind. Wind typically transports snow from the upwind sides of terrain features and deposits snow on the downwind side. Wind slabs are often smooth and rounded and sometimes sound hollow, and can range from soft to hard. Wind 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.