Avalanche Forecast

Issued: Apr 2nd, 2013 10:07AM

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

mbender, Avalanche Canada

South Columbia.

Summary

Confidence

Fair - Timing or intensity of solar radiation is uncertain for the entire period

Weather Forecast

Wednesday: Overcast skies / Light northwest winds / Freezing level at 1700mThursday: A high pressure system builds promoting clear and dry conditions with light westerly winds and 1800m freezing levels.Friday: An upper trough of low pressure will move over the Interior on Friday bringing light to locally moderate precipitation. Freezing levels will be in the valley bottom in the morning and rise to 2000m in the afternoon.

Avalanche Summary

Solar aspects have been very active showing lots of natural loose wet and wet slab avalanches and cornice releases up to size 2.5.

Snowpack Summary

Surface faceting and surface hoar growth ( up to 20 mm) has been prevalent on shady slopes at upper elevations, while the surface snow on sun-exposed slopes and at lower elevations has been subject to daily melt-freeze cycles. Cornices are large and weak.Surface hoar buried March 10th is down 100cm in most places. This layer seems to be bonding in most places and is a low probability - high consequence problem. Triggering may be possible with a very large load (cornice fall) or hitting the sweet spot in thin, variable snowpack areas.

Problems

Cornices

Cornice falls are a concern during warming. Slopes with corniced entrances, or exposed to cornice falls should be avoided. It is possible that the weight of a cornice dropping onto the slope below could trigger an avalanche on the Mid-March crust.

Cornices become weak with daytime heating, so travel early on exposed slopes.>Extra caution needed around cornices with current conditions.>

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

Elevations: Alpine.

Likelihood

Possible

Expected Size

2 - 6

Loose Wet

Keep an eye on changing conditions: Avalanche activity, snowballing, moist and wet snow are initial indicators of deterioration and increased hazard.

Avoid sun exposed slopes when the solar radiation is strong, especially if snow is moist or wet.>Be alert to conditions that change with elevation.>

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

Elevations: All elevations.

Likelihood

Possible - Likely

Expected Size

1 - 4

Valid until: Apr 3rd, 2013 2:00PM