Start early to take advantage of good travel conditions and cool temperatures on Tuesday morning. We expect the hazard will rise later in the day as things warm up and the precipitation arrives.
Weather Forecast
Tuesday will start out as a mix of sun and cloud with below freezing temperatures overnight helping with travel conditions. Some precipitation is expected to arrive Tuesday afternoon with up to 5-10 cm accompanied by strong West winds and freezing levels up to 2300m. Cooler temps and slightly drier conditions with some cloud is expected Wednesday.
Snowpack Summary
Moderate west winds over the past 24 hrs have created wind effect in open areas, and wind slabs in lee areas in the alpine, On solar aspects the March 15 sun crust is down 25-50 cm and has been sensitive to skier triggering over the last week. A temperature crust is present on all aspects below 2000m and higher on solar aspects.
Avalanche Summary
Some loose dry sluffing in the alpine due to strong wind gusts on Monday, as well as thin touchy wind slabs in immediate lee areas at local ski hills. Explosive control at Sunshine produced one size 2 wind slab. On Sunday a size 2 wind slab was observed on a NE aspect at 2600m near Lake Louise and some loose wet sluffing out of steep solar terrain.
Confidence
Timing of incoming weather systems is uncertain on Tuesday
Problems
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.
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.