Register
Get forecast notifications
Create an account to receive email notifications when forecasts are published.
Login
Archived

Avalanche Forecast

Dec 20th, 2012–Dec 21st, 2012
Alpine
2: Moderate
The avalanche danger rating in the alpine will be moderate
Treeline
2: Moderate
The avalanche danger rating at treeline will be moderate
Below Treeline
1: Low
The avalanche danger rating below treeline will be low
Alpine
2: Moderate
The avalanche danger rating in the alpine will be moderate
Treeline
2: Moderate
The avalanche danger rating at treeline will be moderate
Below Treeline
1: Low
The avalanche danger rating below treeline will be low
Alpine
2: Moderate
The avalanche danger rating in the alpine will be moderate
Treeline
1: Low
The avalanche danger rating at treeline will be low
Below Treeline
1: Low
The avalanche danger rating below treeline will be low
Mod. to strong winds from the S/SW are creating a fresh instability to watch out for. Periods of strong winds will also increase sluffing out of steep terrain (ice climbers beware). Winds should ease on Friday allowing the danger to decrease.

Weather Forecast

Thurs overnight: Alpine temps -10/-15. 2-5 cm snow. Alpine winds moderate from the SW.Fri: Alpine temps -10/-15. Clearing skies, trace precip. Alpine winds light from the SW.Sat: Alpine temps -10/-15. Overcast, trace precip. Alpine winds light from the S.Sun: Alpine temps -10/-15. Overcast, trace precip. Alpine winds light from the SW.

Snowpack Summary

10-20 cms of new snow overlies a well settled midpack. At ridgetop elevations, moderate to strong S/SW winds are forming 15-30 cm soft slabs in the immediate lee on N through E aspects. The Nov. 6th crust is facetting out, and is now more of a facet layer than a crust in many places. This layer is giving hard to no results in compression tests.

Avalanche Summary

Limited observations by Parks staff today.  Reports of ski cutting soft slabs in wind loaded areas by ski patrol at Sunshine and loose snow sluffing out of steep terrain with increased winds.

Confidence

Due to the number of field observations on Thursday

Avalanche Problems

Wind Slabs

10-20 cms of new snow along with mod. S/SW winds is creating slabs up to 40 cms thickĀ  in immediate lees at ridgetop elevations. This new instability has been reactive to skier traffic with ski cutting to size 1.5.
Be cautious as you transition into wind affected terrain.Stay off recent wind loaded areas until the slope has had a chance to stabilize.

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

Elevations: Alpine, Treeline.

Likelihood: Possible - Likely

Expected Size: 1 - 2