Avalanche Forecast

Issued: Mar 16th, 2016 8:09AM

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

pmarshall, Avalanche Canada

Sea To Sky.

Strong sunshine will increase avalanche danger during the day. Plan your route to minimize exposure to big sun-drenched slopes in the afternoon.

Summary

Confidence

High

Weather Forecast

THURSDAY: Mainly sunny. The freezing level is around 1400-1600 m. Ridge winds are moderate from the northeast. FRIDAY: Mainly sunny. The freezing level should jump to around 2000 m and ridge winds are generally light. SATURDAY: Increasing cloud. The freezing level is around 1800 m and winds remain light.

Avalanche Summary

Recent avalanche activity is primarily limited to natural and explosive-triggered cornice falls. Some of these have been large (size 3) with only a few triggering slabs on the slope below. On Tuesday, one explosive triggered cornice triggered a 1-2 m deep slab on the slope below that released on an old weakness. Forecast sunshine and warming will likely increase cornice activity and result in loose sluffing from steep sun exposed slopes.

Snowpack Summary

Up to 120cm of snow fell over the last week or so. This snow is reported to be settling and gaining strength, but lingering storm instabilities may still exist, especially in recently wind loaded terrain features. Cornices are reported to be large and fragile. Expect to encounter a sun crust or moist snow on sun-exposed slopes depending on the time of day. The mid and lower snowpack are generally strong and well-settled.

Problems

Wind Slabs

We could see some fresh wind loading in immediate lee terrain from northeasterly winds on Thursday. Sun and afternoon warming may increase the sensitivity of triggering a slab.

Minimize exposure to sun exposed slopes when the solar radiation is strong. >Be cautious as you transition into wind affected terrain. >The new snow may require several days to settle and stabilize. >

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

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

1 - 4

Cornices

Cornices are reported to be large and weak. Natural cornice releases are possible with sun exposure and warming.

Extra caution needed around cornices with current conditions.>Give cornices a wide berth when travelling on or below ridges.>

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

Elevations: Alpine.

Likelihood

Possible

Expected Size

2 - 5

Loose Wet

Loose wet sluffing is likely in steep sun-exposed terrain during the day.

Avoid sun exposed slopes when the solar radiation is strong, especially if snow is moist or wet.>Be cautious of sluffing in steep terrain.>

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

Elevations: All elevations.

Likelihood

Likely

Expected Size

1 - 3

Valid until: Mar 17th, 2016 2:00PM