Avalanche Forecast

Issued: Feb 20th, 2013 10:05AM

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

jfloyer, Avalanche Canada

South Rockies.

A good sized storm is poised to hit the region late on Friday. Avalanche danger will increase accordingly.

Summary

Confidence

Fair - Timing of incoming weather is uncertain on Friday

Weather Forecast

Synopsis: A storm impacts this region late on Friday.Thursday: Dry. Winds light westerly. Freezing level around 1000 m.Friday: 5-10 cm new snow is expected, starting late in the day. Extreme southwesterly winds to 90 km/h at ridgetop. Freezing level 1100 m.Saturday: Light snow in the morning, dry in the afternoon. Winds becoming light northwesterly. Freezing level 1000 m.

Avalanche Summary

Small loose snow avalanches have been reported in the recent new snow.

Snowpack Summary

Southeastern parts of the region have seen 30-50cm new snow in the last few days, while western areas have seen more like 10-20 cm. Mostly this snow has been light and overlies old wind slabs on higher north and east facing terrain and sun crusts on solar aspects. There may be localized areas where the wind has blown the new snow into isolated wind slabs in exposed areas. A surface hoar/facet/sun crust layer from mid February (12th) may be buried in the top 35 cm or so, but has not been widely reported from this region. Mid and lower snowpack layers are generally well settled and stable.

Problems

Wind Slabs

Relatively light but locally gusty winds have created wind slabs near ridge lines in exposed areas. If the wind picks up, expect this problem to become more widespread.

Watch freshly wind loaded features.>

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

Elevations: Alpine, Treeline.

Likelihood

Unlikely - Possible

Expected Size

1 - 4

Valid until: Feb 21st, 2013 2:00PM