Regions
Northwest Inland.
Localized solar radiation, snow amounts and wind values may be higher than forecast. Use a conservative approach and watch for signs of instabilities like natural avalanche activity.
Confidence
Poor - Due to the number of field observations
Weather Forecast
The current weather pattern is more winteresque than it has been all season. Im beginning to feel seasonally confused. The lull before the storm is over, and the next one arrives in coastal and inland regions late tonight. Wednesday will be fairly stormy with precipitation amounts 5-15 mm. Ridgetop winds will be strong from the SW and freezing levels will hover near 900 m. On Thursday, up to 10 mm of precipitation is expected with continued strong west winds. Friday will be unsettled with light precipitation amounts and high solar in localized areas. Freezing levels will rise to 1000 m. A strong upper level ridge will set up over the province through the weekend and remain stationary until Tuesday bringing warm air and clear skies.
Avalanche Summary
No new avalanche observations have been reported. On Wednesday, touchy wind slabs and storm slabs are likely, especially in areas that receive higher snowfall amounts or localized solar radiation.
Snowpack Summary
Recent storm snow has likely formed touchy storm slabs. Strong westerly winds have redistributed this new snow and has formed wind slabs on leeward slopes and behind terrain features. The lack of bond between the new wind slabs and storm slabs over the older snow surfaces buried on April 9 th (surface hoar, crusts and facets) are the primary concern. The March 25th surface hoar / crust layer is reportedly unreactive, however; with the new load of wind and snow this should remain on your radar as it may re-awaken, initiating very-large and destructive avalanches. Large ripe cornices are also of concern and will be a problem with additional loading, especially when the sun and warm temperatures come back.
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.