Avalanche Forecast
Issued: Apr 17th, 2015 4:00PM
The alpine rating is , the treeline rating is , and the below treeline rating is Known problems include Loose Wet, Cornices and Wind Slabs.
conrad janzen,
Avalanche Canada
We are gradually moving into true spring melt- freeze conditions although higher N facing terrain still has a winter snowpack. Start early, minimize exposure to steep solar aspects later in the afternoon, and enjoy the fast travel.
Summary
Weather Forecast
Winds are forecast to switch to the North and calm down on Friday night as a ridge of high pressure begins to build. No new precipitation is expected on Saturday or Sunday. Freezing levels should start at valley bottom overnight but rise to 2100m on Saturday and 2200m on Sunday. Early starts and finishes will be important.
Snowpack Summary
Moist snow up to 2100m on all aspects and to ridge top on all solar aspects. Lots of wind effect in alpine areas. Recent wind slabs are beginning to bond but may still be an issue at higher elevations. Cornices are a major concern with the winds and warm temperatures. Recent cornice failures have triggered the basal facets in thin snowpack areas.
Avalanche Summary
Wet loose natural avalanches up to size 2 were seen Friday afternoon with the warm temperatures. Isolated whumpfing was still noted in the Observation Sub Peak area Thursday and was likely due to new wind slabs sitting over sun crust. On Wednesday, a large cornice release triggered a size 3 avalanche on the basal facets in the Sunshine backcountry.
Confidence
Problems
Loose Wet
Expect an increase in solar triggered avalanche activity with daytime heating over the weekend. Start early and be off steep solar aspects by midday.
- Avoid sun exposed slopes when the solar radiation is strong, especially if snow is moist or wet.
Aspects: North, North East, East, South East, South.
Elevations: All elevations.
Likelihood
Expected Size
Cornices
Many large cornices have formed recently, and there have been numerous reports of cornice failures over the last week. In isolated events and thinner snowpack areas, these have been big enough to trigger the deep basal facets.
- Extra caution needed around cornices with current conditions.
- Cornices become weak with daytime heating, so travel early on exposed slopes.
Aspects: North, North East, East, South East.
Elevations: Alpine.
Likelihood
Expected Size
Wind Slabs
Wind slabs are becoming less reactive, but watch for how these are bonding to the harder surfaces below especially on high N aspects.
- Be careful with wind loaded pockets, especially near ridge crests and roll-overs.
Aspects: North, North East, East, South East.
Elevations: Alpine.
Likelihood
Expected Size
Valid until: Apr 18th, 2015 4:00PM
