Avalanche Forecast
Issued: Apr 23rd, 2019 3:57PM
The alpine rating is , the treeline rating is , and the below treeline rating is Known problems include Wind Slabs and Loose Wet.
jsmith,
Avalanche Canada
Lingering wind slabs may still be reactive to human triggers; especially on lee features below alpine ridgetops.
Summary
Confidence
Moderate - Due to the number of field observations
Weather Forecast
TUESDAY NIGHT: Mostly cloudy with isolated alpine flurries; 1-3 cm / Light, northwesterly winds / Alpine low -4 C / Freezing level 1300 m.
WEDNESDAY: Mix of sun and cloud / Moderate, northwesterly winds / Alpine high 0 C / Freezing level 1500 m.
THURSDAY: Sunny / Light, westerly winds / Alpine high 3 C / Freezing level 2000 m.
FRIDAY: Cloudy with isolated alpine flurries; 0-3 cm / Light, southeasterly winds / Alpine high 1 C / Freezing level 1800 m.
Avalanche Summary
No new avalanches were reported in this region on Monday. However, there are currently very few professional observers submitting daily observations. Please submit your observations to the MIN. Photos of avalanches or current conditions are particularly useful.
On Saturday, numerous, natural loose wet avalanches up to size 1.5 were reported on steep solar aspects at treeline and above in the afternoon.
A widespread storm slab avalanche cycle to size 3.5 on all aspects in the alpine was reported on Friday. Although not in this region, check out these two MIN reports from Saturday in Glacier National Park HERE. and HERE.
Snowpack Summary
30-40 mm of rain has soaked the snowpack at treeline and below. The rain/snow boundary on Friday was around 2100 m. New snow amounts in the alpine will taper rapidly with elevation and likely equate to around 15-25 cm of moist snow at upper elevations adding to the 20-40 cm recent snow which overlies a crust everywhere except high elevation, north facing terrain where preserved surface hoar (weak, feathery crystals) may be present in isolated locations down 30-60 cm. A similar layer buried in early April is down 50-80 cm. Smaller storm slab avalanches may step down to one of these deeper weak layers.
Below treeline, snow is disappearing rapidly.
Problems
Wind Slabs
Lingering wind slabs may still be reactive to human triggers; especially on lee features below alpine ridgetops.
- Use small slopes without consequence to test the bond of the recent snow.
- Pay attention to changing conditions with elevation/aspect.
- Be careful with wind loaded pockets, especially near ridge crests and roll-overs.
Aspects: North, North East, East, South East, North West.
Elevations: Alpine.
Likelihood
Expected Size
Loose Wet
Strong solar radiation may trigger loose wet avalanches on steep terrain; especially at upper elevations where there is new snow.
- A moist/wet snow surface, pinwheeling and natural avalanches all indicate a weakening snowpack.
- Avoid terrain traps such as cliffs and gullies that increase the consequence of small avalanches.
Aspects: North East, East, South East, South, South West, West, North West.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Valid until: Apr 24th, 2019 2:00PM
