Avalanche Forecast

Issued: Apr 4th, 2015 9:05AM

The alpine rating is moderate, the treeline rating is moderate, and the below treeline rating is low. Known problems include Wind Slabs and Cornices.

rbuhler, Avalanche Canada

South Rockies.

Snowpack and avalanche observations are becoming scarce. If you've been in the backcountry, please tell us what you've seen here on the Mountain Information Network.

Summary

Confidence

Fair - Timing, track, or intensity of incoming weather system is uncertain

Weather Forecast

A storm system to the south of the border is creating unsettled conditions for the region. On Sunday, mostly cloudy conditions are expected with light scattered flurries. Alpine winds are expected to be strong from the NE to E and freezing levels are expected to reach around 1400m in the afternoon. More organized precipitation is expected for the region Sunday overnight and Monday. Models are currently showing 5-10mm but locally greater amounts are possible in eastern upslope areas. Alpine winds are forecast to be strong from the NE to E and freezing levels are expected to reach around 1400m. A ridge of high pressure builds on Tuesday and should bring dry and mainly clear conditions for the rest of the week. Freezing levels are expected to reach around 2000m on Tuesday and progressively climb higher later in the week.

Avalanche Summary

Observations are becoming very limited as we enter spring. If you're out in the mountains, please consider posting your observations to our webpage. On Thursday, some loose sluffing was reported from steep terrain. On Saturday in the Lizard region, widespread sluffing was reported from steep terrain features and ski cutting produced soft slabs in wind loaded features. On Sunday, it may be possible to trigger new wind slabs in the alpine and exposed areas at treeline. Cornices may become touchy during the heat of the day. If the sun is out during the heat of the afternoon, extra caution should be given to all steep south facing slopes.

Snowpack Summary

10-15cm of recent snowfall overlies a widespread supportive melt-freeze crust. Gusty winds have likely redistributed the surface snow resulting in wind slab formation in the alpine and exposed areas at treeline. The mid-March rain crust is down 35 to 70cm and has shown a good bond with snow above. Old persistent weak layers are still intact in the mid and lower snowpack and there may be potential for these layers to wake up with a big cornice fall, sustained warming and/or a significant rain event.

Problems

Wind Slabs

Light snowfall and moderate-strong winds have likely formed new wind slabs in exposed higher elevation terrain. Watch for triggering in the lee of ridge crests and in gullies.

Be careful with wind loaded pockets, especially near ridge crests and roll-overs.>Travel on ridgetops to avoid wind slabs on slopes below, but be careful with cornices!>

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

1 - 2

Cornices

Large cornices exist at ridge top, and may fail under the weight of a rider. As spring conditions evolve, remember that destructive cornice falls become more likely during periods of warming and solar radiation.

Give cornices a wide berth when traveling on or below ridges. Remember that cornices become weak with daytime heating.>

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

Elevations: Alpine.

Likelihood

Possible

Expected Size

1 - 4

Valid until: Apr 5th, 2015 2:00PM