Avalanche Forecast

Issued: Apr 10th, 2014 9:54AM

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

swerner, Avalanche Canada

Northwest Inland.

Winter transitions into spring! Rapid warming and intense solar radiation can increase the avalanche danger quickly. Check out the new Forecaster Blog which is directly focused on the Northern Regions.

Summary

Confidence

Fair - Timing or intensity of solar radiation is uncertain on Saturday

Weather Forecast

Light-moderate precipitation is expected to come to an end on Friday as a strong ridge dominates the region bringing clear skies and rising freezing levels. Friday: Cloudy in the am with sunny breaks in the afternoon. Ridgetop wind moderate from the NW. Freezing levels rising to 1100 m. Saturday: A mix of sun and cloud. Alpine temperatures high of 2.0 degrees. Ridgetop winds light from the SE. Freezing levels near 1700 m rising to 2000 m overnight.Sunday: Mainly sunny skies. Alpine temperatures high of 7.0 degrees and freezing levels rising to 2200 m. Ridgetop winds light from the SW.

Avalanche Summary

Natural avalanche activity over the past couple of days, sometimes photos say more then words...Check out the link belowHankin-Evelyn Trail-crew update

Snowpack Summary

Up 30 cm of new snow fell at upper elevations and up to 40 mm of rain. A strong rain crust exists up to 2000 m on all aspects. At higher elevations the new snow fell onto a variety of old snow surfaces consisting of surface hoar, facets and melt freeze crusts. Strong SW winds have built thick wind slabs on leeward aspects and a poor bond may exist, especially on a buried crust.At lower elevations (1200 m and below), surface snow is moist and/ or wet, creating melt-freeze conditions.Two persistent weak interfaces exist deeper in the snowpack. The early March layer can be found down 75 - 100cm. The early February crust/facet/surface hoar combo is down 150 - 200cm. Recently, these layers have become overloaded with the new load from snow, rain and wind. They must remain on your radar, and could become reactive with Sunday's solar radiation and super high freezing levels.

Problems

Wind Slabs

Recent strong SW winds have transported new storm snow to leeward slopes and behind terrain features. These wind slabs may be easily triggered by the weight of a person. Solar radiation and warming can make large, looming cornices weak.

Extra caution needed around cornices with current conditions.>Avoid cross loaded and leeward slopes at or above treeline.>

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

Elevations: Alpine, Treeline.

Likelihood

Likely

Expected Size

1 - 4

Deep Persistent Slabs

Two buried weak layers exist in the snowpack. These weak layers could be activated by cornice fall, a surface avalanche in motion, a rider finding the sweet spot, or new load from snow/ rain/ wind.

Be aware of the potential for large, deep avalanches due to the presence of buried facets and surface hoar.>

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Unlikely - Possible

Expected Size

3 - 7

Loose Wet

With warmer temperatures, limited overnight re-freeze and rain forecast, loose wet avalanches are likely.

Avoid exposure to terrain traps where the consequences of a small avalanche could be serious.>Avoid slopes when temperatures rise and the surface snow becomes moist or wet and shows signs of instability, like pinwheels and natural avalanches.>

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Likely

Expected Size

1 - 3

Valid until: Apr 11th, 2014 2:00PM