Avalanche Forecast

Issued: Apr 17th, 2016 9:41AM

The alpine rating is below threshold, the treeline rating is below threshold, and the below treeline rating is below threshold. Known problems include Storm Slabs, Cornices and Loose Wet.

Avalanche Canada ghelgeson, Avalanche Canada

Monday is expected to dawn warm/cloudy and will likely finish cool/sunny. You need to stay alert and make sure your travel plans are in-tune with the rapidly changing conditions if you're headed to the mountains Monday.

Summary

Weather Forecast

Winter and summer will continue to battle it out Monday before a sustained warm-up begins Tuesday morning.  MONDAY:  Overcast skies initially, clearing late in the afternoon, freezing level starting near 2500m, lowering to around 1200m by the afternoon, strong to extreme south/southwest wind, 2 to 15 mm of precipitation expected.  TUESDAY: Scattered cloud cover, freezing level beginning around 800m, climbing to about 2500m in the afternoon, light southwest at treeline, strong southwest wind at ridge top, no significant precipitation expected. WEDNESDAY:  Clear skies at dawn, cloud cover building through the day, freezing level holding around 2000m, light to moderate southwest wind, no precipitation expected.

Avalanche Summary

On Saturday, reported avalanche activity was limited to control work induced wind slabs to size 1.5 on a north facing piece of terrain around 1500m.  Remember that we have very few eyes & ears still in the mountains at this time.

Snowpack Summary

10 to 30 cm of new storm snow has fallen above 1500m in the last last few days. The wind has primarily been out of the south during the storm, which has likely formed fresh wind slabs and created new cornice growth. The storm snow has buried a widespread melt-freeze crust which was thought to exist almost everywhere, the exception may be high elevation north facing terrain. Any old layers in the midpack or at the ground are dormant for now, and the snowpack may just gracefully melt away. However, these layers have the potential to wake up; the hottest weather of the year is expected over the next few days which might test almost forgotten layers.

Problems

Storm Slabs

An icon showing Storm Slabs
New storm slabs at high elevations with additional wind slabs on northerly aspects. Storm snow rests on a crust in many locations which could increase the sensitivity to human-triggering.
The new snow will require a day or two to strengthen and settle in.>Be alert to conditions that change with elevation.>Avoid all avalanche terrain during periods of heavy loading from new snow, wind, or rain.>

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Possible - Likely

Expected Size

1 - 4

Cornices

An icon showing Cornices
New snow and strong southwest wind will help existing trophy sized cornices grow new noses. This may lead to natural cornice failure Monday.
Continue to watch and limit your exposure to overhead cornices and give these monsters an extra wide berth when traveling on or below ridges. >

Aspects: North, North East, East, South East, South.

Elevations: Alpine.

Likelihood

Possible

Expected Size

2 - 5

Loose Wet

An icon showing Loose Wet
Rising temperatures and the potential for periods of direct sunshine on Monday could initiate a fresh round of loose wet activity as the storm snow quickly looses cohesion.
Look for signs of surface instabilities such as pinwheeling and point releasing near cliffs.>Avoid sun exposed slopes when the solar radiation is strong, especially if snow is moist or wet.>

Aspects: North, North East, East, South East.

Elevations: Alpine, Treeline.

Likelihood

Possible - Likely

Expected Size

1 - 3

Valid until: Apr 18th, 2016 2:00PM