The Pineapple Express is on its way! We can expect temperatures to rise, winds to pick up and potentially 20cm of new snow. Be extra cautious and aware of rising temps and increasing hazard. MM
Confidence
Fair - Track of incoming weather is uncertain
Weather Forecast
The Pineapple Express is on its way! Temperatures are going to rise significantly overnight Thursday, and stay high for Friday & Saturday. Precip amounts associated with the Pineapple Express is still up in the air (sorry for the bad pun). Amounts may vary, but for now up to 18cm of snow can be expected at higher elevations, and there is potential for rain at valley bottom. To top it off, the winds will be rocketing out of the west. 120KM at 3000m. Batten down the hatches!
Avalanche Summary
Numerous moist avalanches and pinwheeling at TL on south aspects from yesterday. There was one natural cornice triggered avalanche (SZ 1) at 2400m, on a south aspect slope. No slab propagated, however it did entrain a fair amount on snow.
Snowpack Summary
HN 7cm at TL today. Moderate west winds have redistributed this storm snow making for variable amounts at ALP & TL elevations. The infamous windslab layers sit below this. At TL there are a variety of these slabs sitting on the hardslab, now down 50. In ALP areas, the hardslab is closer to the surface, and still exposed in certain areas. Tests revealed a moderate shear down 25 at TL, however the results were inconsistent from area to area. BTL the snowpack has gained some strength and is now supportive.
Problems
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.